/* --- GLOBAL THEME & VARIABLES --- */
:root {
    /* --- LIGHT THEME (Default) --- */
    --bg-body: #F2F4F8;
    /* Neutral Cool Grey */
    --bg-gradient: linear-gradient(135deg, #e0e7ff 0%, #f3f4f6 100%);

    --text-main: #111827;
    --text-muted: #6b7280;
    --text-light: #ffffff;

    /* Glassmorphism Bases */
    --glass-bg: rgba(255, 255, 255, 0.65);
    --glass-border: rgba(255, 255, 255, 0.4);
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.07);
    --glass-highlight: rgba(255, 255, 255, 0.8);

    /* Cards */
    --card-bg: rgba(255, 255, 255, 0.7);
    --card-bg-hover: rgba(255, 255, 255, 0.9);
    --card-border: rgba(255, 255, 255, 0.5);
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --card-hover-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Accents */
    --accent-primary: #2563eb;
    /* Royal Blue */
    --accent-glow: rgba(37, 99, 235, 0.3);
    --accent-text: #eff6ff;

    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;

    /* Status Badges */
    --status-ready-bg: #10b981;
    --status-ready-text: #fff;
    --status-soon-bg: #94a3b8;
    --status-soon-text: #fff;

    /* Sidebar */
    --sidebar-bg: rgba(15, 23, 42, 0.95);
    /* Nearly opaque dark blue */
    --sidebar-text: #cbd5e1;
    --sidebar-hover: rgba(255, 255, 255, 0.1);
    --sidebar-active: #3b82f6;

    /* Spacing & Radius */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
}

@media (prefers-color-scheme: dark) {
    :root {
        /* --- DARK THEME --- */
        --bg-body: #0f172a;
        /* Slate 900 */
        --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);

        --text-main: #f8fafc;
        --text-muted: #94a3b8;

        /* Glassmorphism Bases Dark */
        --glass-bg: rgba(30, 41, 59, 0.6);
        --glass-border: rgba(255, 255, 255, 0.1);
        --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
        --glass-highlight: rgba(255, 255, 255, 0.05);

        /* Cards */
        --card-bg: rgba(30, 41, 59, 0.6);
        --card-bg-hover: rgba(51, 65, 85, 0.8);
        --card-border: rgba(255, 255, 255, 0.1);
        --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
        --card-hover-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.6);

        /* Accents */
        --accent-primary: #3b82f6;
        --accent-glow: rgba(59, 130, 246, 0.4);
    }
}

/* --- RESET & TYPOGRAPHY --- */
* {
    box-sizing: border-box;
    outline: none;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background: var(--bg-body);
    background-image: var(--bg-gradient);
    background-attachment: fixed;
    color: var(--text-main);
    margin: 0;
    padding: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    line-height: 1.6;
    transition: background 0.5s ease;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    margin: 0 0 1rem 0;
    font-weight: 700;
    color: var(--text-main);
    letter-spacing: -0.02em;
    line-height: 1.2;
}

h1 {
    font-size: 3rem;
    font-weight: 800;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: 1.5rem;
    color: var(--text-muted);
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.2s ease;
}

/* --- UTILITIES --- */
.hidden {
    display: none !important;
}

@media (min-width: 769px) {
    .lg\:hidden {
        display: none !important;
    }
}

.text-center {
    text-align: center;
}

.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.items-center {
    align-items: center;
}

.justify-center {
    justify-content: center;
}

.w-full {
    width: 100%;
}

.mt-4 {
    margin-top: 1rem;
}

.mb-4 {
    margin-bottom: 1rem;
}

/* --- GLASSMORPHISM COMPONENTS --- */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    border-radius: var(--radius-md);
}

/* --- HEADER (Hub Style) --- */
.hub-header {
    padding: 100px 20px 60px;
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
    animation: fadeDown 1s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.hub-header h1 {
    font-size: 3.5rem;
    letter-spacing: -0.04em;
    background: linear-gradient(135deg, var(--text-main) 0%, var(--text-muted) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-muted);
    font-weight: 400;
}

/* --- SEARCH --- */
.search-wrapper {
    margin-top: 3rem;
    position: relative;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.search-input {
    width: 100%;
    padding: 1.2rem 1.5rem 1.2rem 3.5rem;
    font-size: 1.1rem;
    font-family: inherit;
    border: 1px solid var(--glass-border);
    border-radius: 99px;
    background: var(--glass-bg);
    color: var(--text-main);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    box-shadow: var(--card-shadow);
    transition: all 0.3s ease;
}

.search-input:focus {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    border-color: var(--accent-primary);
    background: rgba(255, 255, 255, 0.8);
}

@media (prefers-color-scheme: dark) {
    .search-input:focus {
        background: rgba(30, 41, 59, 0.9);
    }
}

.search-icon {
    position: absolute;
    left: 1.2rem;
    top: 50%;
    transform: translateY(-50%);
    width: 24px;
    height: 24px;
    color: var(--text-muted);
    pointer-events: none;
    transition: color 0.3s;
}

.search-input:focus+.search-icon {
    color: var(--accent-primary);
}

/* --- CARD GRID --- */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px 100px;
    width: 100%;
    animation: fadeUp 1s cubic-bezier(0.2, 0.8, 0.2, 1) 0.2s backwards;
}

/* --- PREMIUM CARDS --- */
.card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--card-shadow);
    cursor: pointer;
    min-height: 320px;
}

.card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: var(--card-hover-shadow);
    background: var(--card-bg-hover);
    border-color: var(--accent-primary);
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: linear-gradient(90deg, var(--accent-primary), transparent);
    opacity: 0;
    transition: opacity 0.3s;
}

.card:hover::before {
    opacity: 1;
}

.card-icon {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    background: var(--bg-body);
    color: var(--text-main);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 2rem;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.05);
    transition: all 0.4s ease;
}

.card:hover .card-icon {
    background: var(--accent-primary);
    color: var(--accent-text);
    transform: rotate(-10deg) scale(1.1);
    box-shadow: 0 10px 20px var(--accent-glow);
}

.card h2 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--glass-border);
    padding-top: 1.5rem;
    margin-top: auto;
}

.status-badge {
    font-size: 0.75rem;
    font-weight: 700;
    padding: 6px 16px;
    border-radius: 99px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: var(--status-ready-bg);
    color: var(--status-ready-text);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.arrow-icon {
    color: var(--accent-primary);
    transform: translateX(-5px);
    opacity: 0.6;
    transition: all 0.3s ease;
}

.card:hover .arrow-icon {
    transform: translateX(0);
    opacity: 1;
}

/* --- APP / SIDEBAR LAYOUT --- */
.app-container {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 280px;
    background: var(--sidebar-bg);
    color: var(--sidebar-text);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-shrink: 0;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    height: 100vh;
    position: sticky;
    top: 0;
    border-right: 1px solid rgba(255, 255, 255, 0.05);
    overflow-y: auto;
    z-index: 50;
    transition: transform 0.3s ease;
}

.logo-area {
    margin-bottom: 3rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-section-title {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: #64748b;
    margin: 1.5rem 0 0.5rem 0.5rem;
    font-weight: 700;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    color: var(--sidebar-text);
    background: transparent;
    border: none;
    font-size: 0.95rem;
    cursor: pointer;
    width: 100%;
    text-align: left;
    transition: all 0.2s;
    font-weight: 500;
}

.nav-item:hover {
    background: var(--sidebar-hover);
    color: #fff;
    transform: translateX(4px);
}

.nav-item.active {
    background: var(--accent-primary);
    color: white;
    box-shadow: 0 4px 12px var(--accent-glow);
}

/* --- MAIN CONTENT AREA --- */
.main-content {
    flex: 1;
    padding: 3rem 4rem;
    overflow-y: auto;
    background: transparent;
    /* Let body gradient show through */
}

.content-wrapper {
    max-width: 900px;
    margin: 0 auto;
    animation: fadeIn 0.6s ease;
}

/* --- MODULE CONTENT --- */
.content-card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 3rem;
    box-shadow: var(--card-shadow);
    margin-bottom: 2rem;
}

.prose {
    line-height: 1.8;
    font-size: 1.05rem;
}

.prose strong {
    color: var(--text-main);
    font-weight: 700;
}

.prose ul,
.prose ol {
    padding-left: 1.5rem;
    margin-bottom: 1.5rem;
}

.prose li {
    margin-bottom: 0.5rem;
}

/* --- BUTTONS --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    background: var(--accent-primary);
    color: #fff;
    border-radius: var(--radius-sm);
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 4px 6px rgba(37, 99, 235, 0.2);
    font-size: 1rem;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 15px var(--accent-glow);
    filter: brightness(1.1);
}

.btn-secondary {
    background: var(--glass-bg);
    color: var(--text-main);
    border: 1px solid var(--glass-border);
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.9rem;
    font-weight: 500;
}

.btn-secondary:hover {
    background: var(--bg-body);
    border-color: var(--accent-primary);
}

/* --- QUIZ STYLES --- */
.option-btn {
    width: 100%;
    padding: 1.25rem;
    margin-bottom: 1rem;
    background: var(--glass-bg);
    border: 2px solid var(--glass-border);
    /* Thicker border for better visibility */
    border-radius: var(--radius-md);
    font-size: 1rem;
    color: var(--text-main);
    cursor: pointer;
    transition: all 0.2s;
    text-align: left;
    position: relative;
    overflow: hidden;
}

.option-btn:hover:not(:disabled) {
    border-color: var(--accent-primary);
    background: rgba(255, 255, 255, 0.5);
}

@media (prefers-color-scheme: dark) {
    .option-btn:hover:not(:disabled) {
        background: rgba(50, 60, 80, 0.5);
    }
}

.option-btn.correct {
    background: rgba(16, 185, 129, 0.1);
    border-color: var(--success-color);
    color: var(--success-color);
    font-weight: 600;
}

.option-btn.wrong {
    background: rgba(239, 68, 68, 0.1);
    border-color: var(--error-color);
    color: var(--error-color);
    font-weight: 600;
}

/* --- RESPONSIVE --- */
@media (max-width: 1024px) {
    .main-content {
        padding: 2rem;
    }

    .hub-header {
        padding: 80px 20px 40px;
    }
}

@media (max-width: 768px) {
    .app-container {
        flex-direction: column;
    }

    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        bottom: 0;
        transform: translateX(-100%);
        width: 80%;
        max-width: 320px;
        box-shadow: 10px 0 30px rgba(0, 0, 0, 0.5);
    }

    .sidebar.mobile-open {
        transform: translateX(0);
    }

    .main-content {
        padding: 1.5rem;
        width: 100%;
    }

    .card-grid {
        padding: 0 20px 60px;
        gap: 1.5rem;
    }

    h1 {
        font-size: 2.25rem;
    }

    .hub-header {
        padding-top: 60px;
    }

    .search-input {
        padding: 1rem 1rem 1rem 3rem;
        font-size: 1rem;
    }
}

/* --- RESPONSIVE TABLE WRAPPER --- */
.table-responsive {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    margin-bottom: 1rem;
    border-radius: var(--radius-sm);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.table-responsive table {
    width: 100%;
    min-width: 500px;
    /* Prevent squishing */
}

/* --- ANIMATIONS --- */
@keyframes fadeDown {
    from {
        opacity: 0;
        transform: translateY(-40px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}