/* ==========================================================================
   AzureNotes - Study & Note Taking System
   Visually matched to azure-reader.kingorot6.workers.dev
   ========================================================================== */

/* Design Tokens & CSS Variables */
:root {
    --transition-speed: 0.3s;
    --transition-curve: cubic-bezier(0.4, 0, 0.2, 1);
    --font-sans: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-serif: 'Lora', Georgia, 'Times New Roman', serif;
    --font-mono: 'JetBrains Mono', monospace;
    --doc-bg-color: #0f0f12;
    --note-font-size: 16px;
    --note-font-family: var(--font-serif);
    --note-page-width: 820px;
}

/* Night Theme (Default - Matches AzureReader Night) */
body.theme-night {
    --bg-viewport: #0f0f12;
    --bg-panel: rgba(22, 22, 26, 0.94);
    --bg-card: rgba(22, 22, 26, 0.85);
    --text-primary: #e2e8f0;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.18);
    --accent: #818cf8;
    --accent-hover: #6366f1;
    --accent-glow: rgba(129, 140, 248, 0.18);
    --card-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.7);
    --pop-shadow: 0 16px 40px -8px rgba(0, 0, 0, 0.8), 0 0 0 1px rgba(255, 255, 255, 0.08);
}

/* Day Theme Colors */
body.theme-day {
    --bg-viewport: #f8fafc;
    --bg-panel: rgba(255, 255, 255, 0.94);
    --bg-card: rgba(255, 255, 255, 0.88);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --border-color: rgba(0, 0, 0, 0.08);
    --border-hover: rgba(0, 0, 0, 0.16);
    --accent: #4f46e5;
    --accent-hover: #4338ca;
    --accent-glow: rgba(79, 70, 229, 0.12);
    --card-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
    --pop-shadow: 0 16px 40px -8px rgba(0, 0, 0, 0.15), 0 0 0 1px rgba(0, 0, 0, 0.06);
}

/* Sepia Theme Colors (Warm Literary Tone) */
body.theme-sepia {
    --bg-viewport: #f5eedc;
    --bg-panel: rgba(244, 235, 215, 0.96);
    --bg-card: rgba(244, 235, 215, 0.9);
    --text-primary: #3d2a14;
    --text-secondary: #6e5436;
    --text-muted: #9e8568;
    --border-color: rgba(61, 42, 20, 0.1);
    --border-hover: rgba(61, 42, 20, 0.2);
    --accent: #b45309;
    --accent-hover: #92400e;
    --accent-glow: rgba(180, 83, 9, 0.14);
    --card-shadow: 0 10px 25px -5px rgba(61, 42, 20, 0.1);
    --pop-shadow: 0 16px 40px -8px rgba(61, 42, 20, 0.2), 0 0 0 1px rgba(61, 42, 20, 0.1);
}

/* Base Reset & Typography */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-viewport);
    color: var(--text-primary);
    overflow-y: auto;
    overflow-x: hidden;
    min-height: 100vh;
    width: 100vw;
    transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease;
    -webkit-font-smoothing: antialiased;
}

/* Viewport Background Wallpapers */
.viewport-bg-media {
    position: fixed;
    inset: 0;
    width: 100vw;
    height: 100vh;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    pointer-events: none;
    z-index: 0;
    transition: opacity var(--transition-speed) ease, background-image 0.4s ease;
    opacity: 0.35;
}

body.theme-night .viewport-bg-media {
    background-image: url('bg_night.png');
    opacity: 0.4;
}

body.theme-day .viewport-bg-media {
    background-image: url('bg_day.png');
    opacity: 0.25;
}

body.theme-sepia .viewport-bg-media {
    opacity: 0.15;
}

/* App Main Container */
.app-container {
    position: relative;
    width: 100vw;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    z-index: 1;
}

/* ==========================================================================
   Top Navigation Bar (KyBook Floating Style)
   ========================================================================== */
.top-navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 56px;
    background: var(--bg-panel);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-color);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1.25rem;
    box-shadow: var(--card-shadow);
    transition: transform var(--transition-speed) var(--transition-curve), opacity var(--transition-speed) ease;
}

.top-navbar.hidden {
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
}

.nav-left, .nav-right {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.nav-center {
    flex-grow: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: 0 1rem;
}

.nav-title-group {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    max-width: 500px;
    overflow: hidden;
}

.note-subject-pill {
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: var(--accent-glow);
    color: var(--accent);
    border: 1px solid var(--accent);
    padding: 0.15rem 0.5rem;
    border-radius: 6px;
    white-space: nowrap;
}

.book-title {
    font-size: 0.92rem;
    font-weight: 600;
    letter-spacing: 0.01em;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    color: var(--text-primary);
}

/* Minimal Nav Buttons */
.nav-btn {
    background: none;
    border: 1px solid transparent;
    color: var(--text-primary);
    cursor: pointer;
    border-radius: 50%;
    width: 38px;
    height: 38px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    transition: all 0.2s ease;
    position: relative;
}

.nav-btn:hover {
    background: var(--accent-glow);
    color: var(--accent);
    border-color: rgba(255, 255, 255, 0.08);
}

.nav-btn.btn-sm {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    font-size: 1.1rem;
}

/* Mode Toggle Button (Edit / Study) */
.nav-mode-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: var(--accent-glow);
    border: 1px solid var(--accent);
    color: var(--accent);
    font-family: var(--font-sans);
    font-size: 0.78rem;
    font-weight: 600;
    padding: 0.35rem 0.75rem;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.nav-mode-toggle:hover {
    background: var(--accent);
    color: #ffffff;
    box-shadow: 0 0 12px var(--accent-glow);
}

.nav-mode-toggle.active {
    background: var(--accent);
    color: #ffffff;
}

/* Pomodoro Navigation Badge */
.pomodoro-nav-badge {
    position: absolute;
    bottom: -4px;
    right: -4px;
    background: #ef4444;
    color: #ffffff;
    font-size: 0.6rem;
    font-weight: 700;
    padding: 1px 4px;
    border-radius: 8px;
    border: 1px solid var(--bg-panel);
    font-variant-numeric: tabular-nums;
}

/* ==========================================================================
   Theme Dropdown Menu (AzureReader 3-Section System)
   ========================================================================== */
.theme-menu {
    position: absolute;
    top: 62px;
    right: 1.25rem;
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1rem;
    box-shadow: var(--pop-shadow);
    z-index: 1010;
    animation: popIn 0.2s ease-out;
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
    width: 330px;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.theme-menu-title {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.02em;
    padding-bottom: 0.35rem;
    border-bottom: 1px solid var(--border-color);
}

.theme-section-card {
    display: flex;
    flex-direction: column;
    gap: 0.55rem;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0.65rem 0.75rem;
    transition: border-color 0.2s ease;
}

.theme-section-card:hover {
    border-color: var(--border-hover);
}

.theme-row-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
}

.theme-trigger-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    background: none;
    border: none;
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    padding: 0;
    flex-grow: 1;
}

.theme-chevron {
    transition: transform 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    opacity: 0.65;
    margin-left: auto;
}

.theme-trigger-btn.active .theme-chevron {
    transform: rotate(180deg);
}

.color-indicator-swatch {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    display: inline-block;
    border: 1.5px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 1px 3px rgba(0,0,0,0.3);
    flex-shrink: 0;
}

.btn-custom-bg-action {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    background: var(--accent-glow);
    border: 1px solid var(--accent);
    color: var(--accent);
    font-family: var(--font-sans);
    font-size: 0.72rem;
    font-weight: 600;
    padding: 0.25rem 0.55rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-custom-bg-action:hover {
    background: var(--accent);
    color: #ffffff;
}

.color-presets-row {
    display: flex;
    align-items: center;
    gap: 0.45rem;
    flex-wrap: wrap;
    padding: 0.2rem 0;
}

.color-preset-btn {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    cursor: pointer;
    border: 1.5px solid transparent;
    transition: transform 0.15s ease, border-color 0.15s ease;
}

.color-preset-btn:hover {
    transform: scale(1.15);
}

.color-preset-btn.active {
    border-color: var(--accent) !important;
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.custom-color-picker-wrapper {
    position: relative;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    overflow: hidden;
    cursor: pointer;
    border: 1px dashed var(--border-color);
    background: conic-gradient(red, yellow, lime, aqua, blue, magenta, red);
}

.custom-color-picker-wrapper input[type="color"] {
    position: absolute;
    top: -10px;
    left: -10px;
    width: 44px;
    height: 44px;
    border: none;
    cursor: pointer;
    opacity: 0;
}

.doc-palette-row {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.doc-transparent-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.35rem 0.65rem;
    color: var(--text-secondary);
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.doc-transparent-btn:hover, .doc-transparent-btn.active {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-glow);
}

.checkerboard-icon {
    width: 14px;
    height: 14px;
    border-radius: 3px;
    background: repeating-conic-gradient(#808080 0% 25%, transparent 0% 50%) 50% / 8px 8px;
    display: inline-block;
}

/* Settings Menu Dropdown (Export / Print) */
.settings-menu {
    position: absolute;
    top: 62px;
    right: 4.5rem;
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    padding: 0.85rem;
    box-shadow: var(--pop-shadow);
    z-index: 1010;
    animation: popIn 0.2s ease-out;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    width: 250px;
    backdrop-filter: blur(16px);
}

.settings-row {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.settings-row label {
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.2rem;
}

.menu-action-item {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.55rem 0.75rem;
    border-radius: 8px;
    background: none;
    border: 1px solid transparent;
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.82rem;
    font-weight: 500;
    text-align: left;
    cursor: pointer;
    transition: all 0.18s ease;
}

.menu-action-item:hover {
    background: var(--accent-glow);
    color: var(--accent);
    border-color: rgba(255, 255, 255, 0.05);
}

/* ==========================================================================
   Home Screen & Dual Card Layout (AzureReader 1:1 match)
   ========================================================================== */
.initial-upload {
    position: relative;
    width: 100vw;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 3rem 1.5rem;
    z-index: 2;
}

.home-bg-media {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 0;
    pointer-events: none;
    opacity: 0.35;
    transition: opacity 0.3s ease;
}

body.theme-night .home-bg-media {
    opacity: 0.45;
}

body.theme-day .home-bg-media {
    opacity: 0.2;
}

/* Floating shortcuts on Home screen */
.home-vocab-btn {
    position: fixed;
    top: 1.5rem;
    right: 5rem;
    z-index: 10;
    background: var(--bg-card);
    backdrop-filter: blur(14px);
    border: 1px solid var(--border-color);
}

.home-stats-btn {
    position: fixed;
    top: 1.5rem;
    right: 8.5rem;
    z-index: 10;
    background: var(--bg-card);
    backdrop-filter: blur(14px);
    border: 1px solid var(--border-color);
}

.home-theme-circle-btn {
    position: fixed;
    top: 1.5rem;
    right: 1.5rem;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: var(--bg-card);
    backdrop-filter: blur(14px);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: var(--card-shadow);
    transition: all 0.25s ease;
    z-index: 10;
}

.home-theme-circle-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: rotate(20deg) scale(1.05);
}

.home-container {
    display: flex;
    gap: 2.5rem;
    max-width: 1000px;
    width: 100%;
    align-items: flex-start;
    justify-content: center;
    margin: auto 0;
    position: relative;
    z-index: 2;
}

/* Glass Cards */
.upload-card, .library-card {
    background: var(--bg-card) !important;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-color) !important;
    border-radius: 24px;
    padding: 2.5rem 2rem;
    width: 470px;
    box-shadow: 0 20px 45px -15px rgba(0, 0, 0, 0.5), var(--card-shadow);
    animation: fadeIn 0.4s ease-out;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), border-color 0.3s ease, box-shadow 0.3s ease;
    z-index: 2;
    display: flex;
    flex-direction: column;
}

.upload-card:hover, .library-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent) !important;
    box-shadow: 0 15px 35px -5px var(--accent-glow), var(--card-shadow);
}

.brand-badge-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
}

.upload-logo {
    max-height: 48px;
    object-fit: contain;
}

.study-pulse-tag {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    background: var(--accent-glow);
    color: var(--accent);
    border: 1px solid var(--accent);
}

.upload-card h2 {
    font-size: 1.65rem;
    font-weight: 800;
    letter-spacing: -0.01em;
    margin-bottom: 0.5rem;
    text-align: center;
}

.upload-tagline {
    font-size: 0.84rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
    text-align: center;
}

/* Home Settings Section inside Left Card */
.home-lang-settings {
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.9rem;
    text-align: left;
    background: rgba(255, 255, 255, 0.03);
    padding: 1.2rem;
    border-radius: 18px;
    border: 1px solid var(--border-color);
}

.home-lang-row {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.home-lang-row label {
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.lang-select-home {
    width: 100%;
    padding: 0.65rem 1rem;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    background: rgba(15, 15, 18, 0.7);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.25s ease;
    appearance: none;
    -webkit-appearance: none;
    background-image: url("data:image/svg+xml;utf8,<svg fill='%23818cf8' height='24' viewBox='0 0 24 24' width='24' xmlns='http://www.w3.org/2000/svg'><path d='M7 10l5 5 5-5z'/></svg>");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 20px;
    padding-right: 32px;
}

body.theme-day .lang-select-home {
    background-color: #ffffff;
}

.lang-select-home:hover, .lang-select-home:focus {
    border-color: var(--accent);
    outline: none;
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.lang-select-home option {
    background: var(--bg-viewport);
    color: var(--text-primary);
}

.api-key-input-home {
    width: 100%;
    padding: 0.65rem 0.85rem;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    background: rgba(15, 15, 18, 0.7);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.85rem;
    transition: all 0.2s ease;
}

body.theme-day .api-key-input-home {
    background-color: #ffffff;
}

.api-key-input-home:focus {
    border-color: var(--accent);
    outline: none;
    box-shadow: 0 0 0 2px var(--accent-glow);
}

/* Drop Zone (AzureReader 1:1) */
.drop-zone {
    border: 2px dashed var(--border-color);
    background: rgba(255, 255, 255, 0.015);
    border-radius: 16px;
    padding: 1.6rem 1.25rem;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 0.65rem;
    transition: all 0.3s ease;
}

.drop-zone:hover {
    border-color: var(--accent);
    background: var(--accent-glow);
}

.drop-zone svg {
    color: var(--accent);
    transition: transform 0.3s ease;
}

.drop-zone:hover svg {
    transform: translateY(-3px) scale(1.05);
}

.drop-zone p {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* Right Card: Library of Notes */
.library-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.25rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.75rem;
}

.library-card-header h2 {
    font-size: 1.45rem;
    font-weight: 700;
    color: var(--text-primary);
}

.lib-count-badge {
    font-size: 0.72rem;
    font-weight: 700;
    background: var(--accent-glow);
    color: var(--accent);
    border: 1px solid var(--accent);
    border-radius: 12px;
    padding: 0.15rem 0.55rem;
}

.library-search-box {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 0.55rem 0.85rem;
    margin-bottom: 0.85rem;
}

.library-search-box input {
    background: none;
    border: none;
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.82rem;
    width: 100%;
    outline: none;
}

.subject-filter-tags {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    overflow-x: auto;
    padding-bottom: 0.6rem;
    margin-bottom: 0.85rem;
}

.subject-tag-btn {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    border-radius: 16px;
    padding: 0.25rem 0.65rem;
    font-size: 0.72rem;
    font-weight: 600;
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.2s ease;
}

.subject-tag-btn:hover, .subject-tag-btn.active {
    background: var(--accent-glow);
    color: var(--accent);
    border-color: var(--accent);
}

.library-list {
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
    text-align: left;
    max-height: 380px;
    overflow-y: auto;
    padding-right: 0.35rem;
}

/* Custom Scrollbars */
.library-list::-webkit-scrollbar, .drawer-content::-webkit-scrollbar, .note-scroller::-webkit-scrollbar {
    width: 5px;
}
.library-list::-webkit-scrollbar-thumb, .drawer-content::-webkit-scrollbar-thumb, .note-scroller::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.15);
    border-radius: 4px;
}

/* Individual Library Note Item */
.library-item {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--accent);
    padding: 0.95rem 1.15rem;
    border-radius: 14px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    position: relative;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.03);
}

.library-item:hover {
    background: var(--accent-glow);
    border-color: var(--accent);
    transform: translateX(4px);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
}

.lib-info {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
    flex-grow: 1;
    overflow: hidden;
    padding-right: 0.5rem;
}

.lib-header-row {
    display: flex;
    align-items: center;
    gap: 0.45rem;
}

.lib-tag {
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--accent);
    background: var(--accent-glow);
    border-radius: 4px;
    padding: 0.1rem 0.4rem;
}

.lib-title {
    font-size: 0.92rem;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    color: var(--text-primary);
}

.lib-progress-bar-wrapper {
    width: 100%;
    height: 4px;
    background: var(--border-color);
    border-radius: 2px;
    margin: 0.35rem 0 0.2rem 0;
    overflow: hidden;
}

.lib-progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent) 0%, #38bdf8 100%);
    border-radius: 2px;
    transition: width 0.3s ease;
}

.lib-meta-row {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 0.7rem;
    color: var(--text-muted);
}

.lib-actions {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.btn-lib-delete {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.15rem;
    cursor: pointer;
    padding: 0.35rem;
    border-radius: 6px;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-lib-delete:hover {
    color: #ef4444;
    background: rgba(239, 68, 68, 0.15);
}

.empty-library {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.82rem;
    line-height: 1.6;
    padding: 3rem 1.5rem;
    border: 1px dashed var(--border-color);
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.01);
}

.library-footer-actions {
    margin-top: 1rem;
    text-align: center;
}

/* ==========================================================================
   Note Workspace / Reader & Editor (AzureReader KyBook Viewer)
   ========================================================================== */
.reader-viewport {
    flex-grow: 1;
    position: relative;
    width: 100vw;
    min-height: 100vh;
}

.note-workspace-container {
    width: 100vw;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    padding-top: 56px;
    padding-bottom: 70px;
}

/* Floating Markdown Formatting Toolbar */
.markdown-editor-toolbar {
    position: sticky;
    top: 66px;
    z-index: 50;
    display: flex;
    align-items: center;
    gap: 0.35rem;
    background: var(--bg-panel);
    backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    box-shadow: var(--card-shadow);
    padding: 0.4rem 0.8rem;
    border-radius: 12px;
    margin-bottom: 1.25rem;
    animation: popIn 0.2s ease;
}

.tool-btn {
    background: none;
    border: 1px solid transparent;
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.8rem;
    font-weight: 600;
    padding: 0.3rem 0.55rem;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.15s ease;
}

.tool-btn:hover {
    background: var(--accent-glow);
    color: var(--accent);
    border-color: rgba(255, 255, 255, 0.08);
}

.tool-divider {
    width: 1px;
    height: 18px;
    background: var(--border-color);
    margin: 0 0.25rem;
}

.tool-save-indicator {
    font-size: 0.72rem;
    font-weight: 600;
    color: #34d399;
    margin-left: auto;
    padding-left: 0.5rem;
}

/* Note Scroller Area */
.note-scroller {
    width: 100%;
    display: flex;
    justify-content: center;
    padding: 1.5rem 1rem 3rem 1rem;
    overflow-y: auto;
}

/* Paper / Note Document Card (KyBook Reader View) */
.note-page-paper {
    position: relative;
    width: 100%;
    max-width: var(--note-page-width, 820px);
    min-height: 85vh;
    background-color: var(--doc-bg-color, #0f0f12);
    border: 1px solid var(--border-color);
    border-radius: 18px;
    padding: 3rem 3.5rem;
    box-shadow: 0 15px 45px -15px rgba(0, 0, 0, 0.4), var(--card-shadow);
    transition: max-width 0.25s cubic-bezier(0.4, 0, 0.2, 1), background-color var(--transition-speed) ease, color var(--transition-speed) ease;
}

.note-page-paper.doc-transparent {
    background-color: transparent !important;
    border-color: transparent !important;
    box-shadow: none !important;
    padding: 2rem 1.5rem;
}

.note-doc-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: 1.25rem;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.meta-row-left {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.doc-subject-tag {
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: var(--accent-glow);
    color: var(--accent);
    border: 1px solid var(--accent);
    padding: 0.2rem 0.6rem;
    border-radius: 6px;
}

.doc-date-info, .word-counter-badge {
    font-size: 0.78rem;
    color: var(--text-muted);
}

/* Rendered Study Note Typography & Formatting */
.study-rendered-content {
    font-family: var(--note-font-family);
    font-size: var(--note-font-size);
    line-height: 1.85;
    color: var(--text-primary);
    word-break: break-word;
}

.study-rendered-content h1 {
    font-family: var(--font-sans);
    font-size: 2.1rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 1.25rem;
    color: var(--text-primary);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.study-rendered-content h2 {
    font-family: var(--font-sans);
    font-size: 1.45rem;
    font-weight: 700;
    margin-top: 2rem;
    margin-bottom: 0.75rem;
    color: var(--accent);
}

.study-rendered-content h3 {
    font-family: var(--font-sans);
    font-size: 1.15rem;
    font-weight: 600;
    margin-top: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.study-rendered-content p {
    margin-bottom: 1.25rem;
}

.study-rendered-content ul, .study-rendered-content ol {
    margin-bottom: 1.25rem;
    padding-left: 1.5rem;
}

.study-rendered-content li {
    margin-bottom: 0.4rem;
}

.study-rendered-content blockquote {
    border-left: 3px solid var(--accent);
    background: var(--accent-glow);
    padding: 0.75rem 1.25rem;
    margin: 1.25rem 0;
    border-radius: 0 10px 10px 0;
    font-style: italic;
    color: var(--text-secondary);
}

/* Interactive Study Highlight / Word Inspector (AzureReader kelime tıklama stili) */
.study-term {
    cursor: pointer;
    color: var(--accent);
    font-weight: 600;
    border-bottom: 2px dashed var(--accent);
    padding: 0 3px;
    border-radius: 3px;
    transition: all 0.2s ease;
    display: inline-block;
}

.study-term:hover {
    background: var(--accent-glow);
    transform: translateY(-1px);
    box-shadow: 0 2px 8px var(--accent-glow);
}

/* Highlighting styles (with multiple pastel highlighter colors) */
mark.study-highlight {
    background: rgba(245, 158, 11, 0.35);
    color: inherit;
    padding: 0.12rem 0.32rem;
    border-radius: 4px;
    border-bottom: 2px solid #f59e0b;
    cursor: pointer;
    transition: background-color 0.15s ease, filter 0.15s ease;
}

mark.study-highlight:hover {
    filter: brightness(1.22);
}

mark.study-highlight.hl-yellow {
    background: rgba(245, 158, 11, 0.35);
    border-bottom-color: #f59e0b;
}

mark.study-highlight.hl-green {
    background: rgba(16, 185, 129, 0.32);
    border-bottom-color: #10b981;
}

mark.study-highlight.hl-blue {
    background: rgba(59, 130, 246, 0.32);
    border-bottom-color: #3b82f6;
}

mark.study-highlight.hl-pink {
    background: rgba(236, 72, 153, 0.32);
    border-bottom-color: #ec4899;
}

/* Study Callout Boxes */
.callout-box {
    margin: 1.5rem 0;
    padding: 1.15rem 1.35rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.02);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.callout-box.tip {
    border-left: 4px solid #34d399;
    background: rgba(52, 211, 153, 0.08);
}

.callout-box.important {
    border-left: 4px solid #f59e0b;
    background: rgba(245, 158, 11, 0.08);
}

.callout-box.formula {
    border-left: 4px solid #818cf8;
    background: rgba(129, 140, 248, 0.08);
}

.callout-header {
    display: flex;
    align-items: center;
    gap: 0.45rem;
    font-family: var(--font-sans);
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* KaTeX Formulas Styling */
.katex-display {
    margin: 1.25rem 0 !important;
    padding: 0.75rem !important;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    overflow-x: auto;
}

/* Checklists */
.checklist-item {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin-bottom: 0.5rem;
    list-style: none;
}

.checklist-checkbox {
    width: 17px;
    height: 17px;
    accent-color: var(--accent);
    cursor: pointer;
}

/* Markdown Edit View */
.study-edit-container {
    width: 100%;
}

.markdown-textarea {
    width: 100%;
    min-height: 75vh;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.95rem;
    line-height: 1.75;
    resize: vertical;
}

/* Floating Text Selection Popup */
.text-selection-popup {
    position: fixed;
    z-index: 1050;
    display: flex;
    align-items: center;
    gap: 0.35rem;
    background: var(--bg-panel);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
    padding: 0.35rem 0.55rem;
    border-radius: 30px;
    box-shadow: var(--pop-shadow);
    animation: popIn 0.15s ease-out;
}

.popup-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: none;
    border: none;
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.78rem;
    font-weight: 600;
    padding: 0.35rem 0.65rem;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.15s ease;
}

.popup-btn:hover {
    background: var(--accent-glow);
    color: var(--accent);
}

.popup-hl-colors {
    display: flex;
    align-items: center;
    gap: 5px;
    padding-right: 4px;
}

.hl-color-circle {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    border: 2px solid transparent;
    cursor: pointer;
    transition: transform 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
    padding: 0;
}

.hl-color-circle:hover {
    transform: scale(1.2);
}

.hl-color-circle.active {
    border-color: #ffffff;
    box-shadow: 0 0 6px rgba(255, 255, 255, 0.7);
    transform: scale(1.15);
}

.popup-sep {
    width: 1px;
    height: 16px;
    background: var(--border-color);
    margin: 0 3px;
    display: inline-block;
}

/* Preset Width Buttons in Appearance Menu */
.preset-width-btn {
    flex: 1;
    padding: 5px 8px;
    font-size: 0.72rem;
    font-weight: 500;
    font-family: var(--font-sans);
    border-radius: 6px;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.04);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.15s ease;
}

.preset-width-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.preset-width-btn.active {
    background: var(--accent);
    color: #ffffff;
    border-color: var(--accent);
    font-weight: 600;
}

.zoom-btn.active {
    background: var(--accent-glow);
    color: var(--accent);
    border-color: var(--accent);
}

/* ==========================================================================
   Bottom Floating Toolbar (AzureReader 1:1)
   ========================================================================== */
.bottom-toolbar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--bg-panel);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-top: 1px solid var(--border-color);
    padding: 0.65rem 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
    z-index: 100;
    box-shadow: 0 -10px 30px -10px rgba(0, 0, 0, 0.4);
    transition: transform var(--transition-speed) var(--transition-curve), opacity var(--transition-speed) ease;
}

.bottom-toolbar.hidden {
    transform: translateY(100%);
    opacity: 0;
    pointer-events: none;
}

.progress-bar-container {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.page-slider {
    flex-grow: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 4px;
    border-radius: 2px;
    background: var(--border-color);
    outline: none;
    cursor: pointer;
}

.page-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 1px 5px rgba(0, 0, 0, 0.4);
    transition: transform 0.1s ease;
}

.page-slider::-webkit-slider-thumb:hover {
    transform: scale(1.25);
}

.progress-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.78rem;
    color: var(--text-secondary);
}

.progress-left-info {
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.reading-percent-label {
    font-weight: 600;
    color: var(--accent);
}

.toolbar-zoom {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.zoom-btn {
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 0.2rem 0.45rem;
    border-radius: 6px;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.zoom-btn:hover {
    background: var(--accent-glow);
    color: var(--accent);
}

.toolbar-sep {
    width: 1px;
    height: 14px;
    background: var(--border-color);
    margin: 0 0.25rem;
}

/* ==========================================================================
   Sliding Drawers (Left & Right Drawers - AzureReader 1:1)
   ========================================================================== */
.drawer {
    position: fixed;
    top: 0;
    bottom: 0;
    width: 350px;
    background: var(--bg-panel);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-color: var(--border-color);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    box-shadow: var(--pop-shadow);
    transition: transform var(--transition-speed) var(--transition-curve);
}

.drawer-right {
    right: 0;
    border-left: 1px solid var(--border-color);
    transform: translateX(100%);
}

.drawer-right.active {
    transform: translateX(0);
}

.drawer-left {
    left: 0;
    border-right: 1px solid var(--border-color);
    transform: translateX(-100%);
}

.drawer-left.active {
    transform: translateX(0);
}

.drawer-header {
    height: 56px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 1.25rem;
    border-bottom: 1px solid var(--border-color);
}

.drawer-title-group {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.drawer-header h3 {
    font-size: 0.95rem;
    font-weight: 700;
}

.vocab-badge-count {
    font-size: 0.68rem;
    font-weight: 700;
    background: var(--accent-glow);
    color: var(--accent);
    border-radius: 10px;
    padding: 0.15rem 0.5rem;
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    color: var(--text-secondary);
    transition: color 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.close-btn:hover {
    color: var(--accent);
}

.drawer-content {
    flex-grow: 1;
    overflow-y: auto;
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.vocab-search-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.vocab-search-icon {
    position: absolute;
    left: 12px;
    color: var(--text-muted);
}

.vocab-search-input {
    width: 100%;
    padding: 0.6rem 0.8rem 0.6rem 2.2rem;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.03);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.82rem;
    outline: none;
    transition: border-color 0.2s ease;
}

.vocab-search-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-glow);
}

/* Quick Stats in Left Drawer */
.drawer-quick-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0.75rem 0.5rem;
    text-align: center;
}

.quick-stat-item {
    display: flex;
    flex-direction: column;
}

.stat-big {
    font-size: 1.15rem;
    font-weight: 800;
    color: var(--accent);
}

.stat-small {
    font-size: 0.65rem;
    color: var(--text-muted);
    text-transform: uppercase;
}

/* Drawer Note Tree / Subject list */
.drawer-note-tree {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.drawer-subject-group {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.drawer-subject-title {
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    padding: 0.35rem 0.25rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.drawer-note-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.55rem 0.75rem;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid transparent;
    color: var(--text-primary);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.drawer-note-link:hover, .drawer-note-link.active {
    background: var(--accent-glow);
    border-color: var(--accent);
    color: var(--accent);
}

/* Flashcard List in Right Drawer */
.btn-quiz-trigger {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.7rem;
    font-size: 0.85rem;
}

.add-term-collapsible {
    border: 1px dashed var(--border-color);
    border-radius: 10px;
    padding: 0.65rem 0.85rem;
}

.add-term-trigger {
    width: 100%;
    text-align: left;
    font-size: 0.8rem;
    color: var(--accent);
    cursor: pointer;
}

.add-term-form {
    margin-top: 0.6rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.vocab-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.vocab-card-item {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0.85rem 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    transition: all 0.2s ease;
}

.vocab-card-item:hover {
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.035);
}

.vocab-card-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.vocab-term-name {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-primary);
}

.vocab-card-actions {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.btn-vocab-speak {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    transition: color 0.18s ease, transform 0.18s ease;
}

.btn-vocab-speak:hover {
    color: var(--accent);
    transform: scale(1.15);
}

.btn-vocab-delete {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 1rem;
    transition: color 0.2s ease;
}

.btn-vocab-delete:hover {
    color: #ef4444;
}

.vocab-term-def {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.vocab-term-hint {
    font-size: 0.74rem;
    color: #34d399;
    background: rgba(52, 211, 153, 0.08);
    border-radius: 4px;
    padding: 0.2rem 0.4rem;
}

/* Term Detail Drawer (Right side analysis) */
.word-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.75rem;
}

.word-header h2 {
    font-size: 1.35rem;
    font-weight: 700;
    margin-bottom: 0.2rem;
}

.word-meta {
    font-size: 0.8rem;
    color: var(--accent);
    font-weight: 600;
}

.word-book-name {
    font-size: 0.72rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

.speak-btn {
    background: var(--accent-glow);
    border: none;
    color: var(--accent);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.speak-btn:hover {
    background: var(--accent);
    color: white;
}

.translation-body {
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
}

.section-title {
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    font-weight: 700;
}

.meaning {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--accent);
    line-height: 1.5;
}

.context-meaning {
    font-size: 0.88rem;
    line-height: 1.55;
    color: var(--text-secondary);
}

.example-quote {
    font-family: var(--font-serif);
    font-size: 0.85rem;
    line-height: 1.55;
    padding-left: 0.75rem;
    border-left: 2px solid #ef4444;
    color: var(--text-secondary);
}

.example-quote-source {
    font-size: 0.72rem;
    font-style: italic;
    color: var(--text-muted);
    text-align: right;
    display: block;
}

/* ==========================================================================
   Modals: Flashcard Quiz & Pomodoro (AzureReader Modal System)
   ========================================================================== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 1200;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    animation: fadeIn 0.2s ease;
}

/* 3D Flashcard Quiz Modal */
.quiz-modal-card {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 2rem;
    width: 100%;
    max-width: 520px;
    box-shadow: var(--pop-shadow);
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    animation: popIn 0.25s ease;
}

.quiz-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.quiz-progress-text {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--accent);
}

.quiz-card-3d-wrapper {
    perspective: 1000px;
    width: 100%;
    height: 240px;
    cursor: pointer;
}

.quiz-card-flipper {
    position: relative;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
    transition: transform 0.45s cubic-bezier(0.4, 0, 0.2, 1);
}

.quiz-card-flipper.flipped {
    transform: rotateY(180deg);
}

.quiz-card-face {
    position: absolute;
    inset: 0;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    border-radius: 18px;
    border: 1px solid var(--border-color);
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    box-shadow: var(--card-shadow);
}

.quiz-card-front {
    background: radial-gradient(circle at center, rgba(129, 140, 248, 0.08) 0%, rgba(22, 22, 26, 0.95) 75%);
}

.quiz-card-back {
    background: radial-gradient(circle at center, rgba(52, 211, 153, 0.08) 0%, rgba(22, 22, 26, 0.95) 75%);
    transform: rotateY(180deg);
}

.card-hint-badge {
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 0.15rem 0.5rem;
    border-radius: 10px;
    background: var(--accent-glow);
    color: var(--accent);
    margin-bottom: 0.85rem;
}

.card-hint-badge.success {
    background: rgba(52, 211, 153, 0.12);
    color: #34d399;
}

.quiz-term-heading {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.quiz-instruction {
    font-size: 0.78rem;
    color: var(--text-muted);
}

.quiz-back-definition {
    font-size: 1.05rem;
    line-height: 1.6;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.quiz-back-hint {
    font-size: 0.8rem;
    color: #34d399;
    font-weight: 500;
}

.quiz-card-actions {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
}

/* Pomodoro Timer Modal */
.pomodoro-modal-card {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 2rem;
    width: 100%;
    max-width: 440px;
    box-shadow: var(--pop-shadow);
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    animation: popIn 0.2s ease;
}

.auth-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.auth-card-title-group {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.auth-logo-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--accent-glow);
    color: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
}

.auth-subtitle {
    font-size: 0.78rem;
    color: var(--text-muted);
}

.pomodoro-timer-display {
    text-align: center;
    padding: 1.5rem 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.pomodoro-huge-time {
    font-size: 4rem;
    font-weight: 800;
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.03em;
    color: var(--accent);
}

.pomodoro-phase-pill {
    font-size: 0.8rem;
    font-weight: 700;
    padding: 0.25rem 0.85rem;
    border-radius: 20px;
    background: var(--accent-glow);
    color: var(--accent);
}

.pomodoro-modes-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.pomodoro-mode-btn {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    border-radius: 20px;
    padding: 0.4rem 0.85rem;
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.pomodoro-mode-btn.active {
    background: var(--accent);
    color: #ffffff;
    border-color: var(--accent);
}

.pomodoro-controls {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.pomodoro-stats-card {
    display: grid;
    grid-template-columns: 1fr 1fr;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0.85rem;
    text-align: center;
}

.pomo-stat-num {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--accent);
    display: block;
}

.pomo-stat-lbl {
    font-size: 0.7rem;
    color: var(--text-muted);
}

/* ==========================================================================
   Common Button Styles (AzureReader 1:1)
   ========================================================================== */
.btn {
    font-family: var(--font-sans);
    padding: 0.55rem 1.25rem;
    border-radius: 10px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.45rem;
}

.btn-primary {
    background: var(--accent);
    color: #ffffff;
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px var(--accent-glow);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: var(--border-hover);
}

.btn-danger {
    background: rgba(239, 68, 68, 0.15);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: #ef4444;
}

.btn-danger:hover {
    background: #ef4444;
    color: #ffffff;
}

.btn-success {
    background: rgba(52, 211, 153, 0.15);
    border: 1px solid rgba(52, 211, 153, 0.3);
    color: #34d399;
}

.btn-success:hover {
    background: #10b981;
    color: #ffffff;
}

.btn-text {
    background: none;
    border: none;
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    color: var(--text-secondary);
    transition: color 0.2s ease;
}

.btn-text:hover {
    color: var(--accent);
}

.btn-sm {
    padding: 0.35rem 0.75rem;
    font-size: 0.78rem;
}

.btn-lg {
    padding: 0.75rem 1.75rem;
    font-size: 0.95rem;
    flex-grow: 1;
}

/* Input Styles */
.auth-input {
    width: 100%;
    padding: 0.6rem 0.85rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: rgba(15, 15, 18, 0.7);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.82rem;
    outline: none;
    transition: border-color 0.2s ease;
}

.auth-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-glow);
}

/* Utilities & Animations */
.hidden {
    display: none !important;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@keyframes popIn {
    from { transform: scale(0.95); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* ==========================================================================
   Responsive & Print Styles
   ========================================================================== */
@media (max-width: 960px) {
    .home-container {
        flex-direction: column;
        align-items: center;
        gap: 2rem;
    }
    .library-card, .upload-card {
        width: 100%;
        max-width: 480px;
    }
    .note-page-paper {
        padding: 2rem 1.5rem;
    }
    .drawer {
        width: 100vw;
        max-width: 360px;
    }
}

@media print {
    body {
        background: #ffffff !important;
        color: #000000 !important;
    }
    .top-navbar, .bottom-toolbar, .drawer, .modal-overlay, .markdown-editor-toolbar, .viewport-bg-media {
        display: none !important;
    }
    .note-workspace-container {
        padding: 0 !important;
    }
    .note-page-paper {
        border: none !important;
        box-shadow: none !important;
        background: #ffffff !important;
        color: #000000 !important;
        max-width: 100% !important;
        padding: 0 !important;
    }
    .study-term {
        border-bottom: none !important;
        color: #000000 !important;
    }
}