@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap');

:root {
    color-scheme: light;
    --bg-color: #f8fafc;
    --text-color: #1f2937;
    --muted-text: #64748b;
    --card-bg: #ffffff;
    --border-color: #d9e3f0;
    --border-strong: #94a3b8;
    --primary-accent: #0f766e;
    --primary-accent-hover: #115e59;
    --primary-accent-foreground: #ecfeff;
    --secondary-accent: #f97316;
    --secondary-accent-hover: #ea580c;
    --highlight-soft: #e0f2f1;
    --danger: #dc2626;
    --danger-soft: #fee2e2;
    --success: #16a34a;
    --success-soft: #dcfce7;
    --warning: #f59e0b;
    --warning-soft: #fef3c7;
    --info-soft: #e0f2fe;
    --focus-ring: rgba(14, 165, 233, 0.45);
    --nav-bg: rgba(15, 118, 110, 0.08);
    --red-seal-color: #b91c1c;
}

.app-title {
    color: var(--text-color);
}

.app-title-accent {
    color: var(--red-seal-color);
}

.app-nav {
    background: rgba(255, 255, 255, 0.7);
    border: 1px solid var(--border-color);
    border-radius: 9999px;
    padding: 0.35rem 0.5rem;
    backdrop-filter: blur(6px);
    box-shadow: 0 12px 24px -18px rgba(15, 23, 42, 0.45);
}

html.dark {
    color-scheme: dark;
    --bg-color: #0f172a;
    --text-color: #e2e8f0;
    --muted-text: #94a3b8;
    --card-bg: #1e293b;
    --border-color: #334155;
    --border-strong: #475569;
    --primary-accent: #2dd4bf;
    --primary-accent-hover: #14b8a6;
    --primary-accent-foreground: #022c22;
    --secondary-accent: #fb923c;
    --secondary-accent-hover: #f97316;
    --highlight-soft: rgba(45, 212, 191, 0.12);
    --danger: #f87171;
    --danger-soft: rgba(248, 113, 113, 0.2);
    --success: #4ade80;
    --success-soft: rgba(74, 222, 128, 0.18);
    --warning: #fbbf24;
    --warning-soft: rgba(251, 191, 36, 0.18);
    --info-soft: rgba(56, 189, 248, 0.18);
    --nav-bg: rgba(45, 212, 191, 0.15);
    --focus-ring: rgba(125, 211, 252, 0.55);
}

html.dark .app-title {
    color: var(--text-color);
}

html.dark .app-nav {
    background: rgba(15, 23, 42, 0.65);
    border-color: var(--border-strong);
    box-shadow: 0 12px 24px -18px rgba(15, 118, 110, 0.5);
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
}

a,
button,
input,
select,
textarea {
    font-family: inherit;
    background-color: var(--card-bg);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.3s ease, color 0.3s ease;
}

.form-field {
    width: 100%;
    padding: 0.65rem 0.85rem;
    border-radius: 0.75rem;
    border: 1px solid var(--border-color);
    background-color: var(--card-bg);
    color: var(--text-color);
    box-shadow: inset 0 1px 2px rgba(15, 23, 42, 0.08);
}

.form-field:focus-visible {
    border-color: var(--primary-accent);
    box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.12);
}

html.dark .form-field:focus-visible {
    box-shadow: 0 0 0 3px rgba(45, 212, 191, 0.2);
}

button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--focus-ring);
    outline-offset: 2px;
}

select:disabled,
input:disabled,
textarea:disabled {
    background-color: rgba(148, 163, 184, 0.15);
    color: var(--muted-text);
}

select option {
    background-color: var(--card-bg);
    color: var(--text-color);
}

html.dark select option {
    background-color: #0f172a;
    color: var(--text-color);
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    box-shadow: 0 10px 25px -12px rgba(15, 23, 42, 0.25);
}

.page {
    display: none;
    animation: fadeIn 0.4s ease;
}

.page.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.rtl {
    direction: rtl;
}

.nav-btn {
    background-color: transparent;
    border: 2px solid transparent;
    border-radius: 9999px;
    color: var(--muted-text);
    padding: 0.5rem 1rem;
    transition: color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
    white-space: nowrap;
}

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

.nav-btn.active {
    color: var(--primary-accent);
    border-color: var(--primary-accent);
    background-color: var(--primary-accent-foreground);
    box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.08);
}

html.dark .nav-btn.active {
    box-shadow: 0 0 0 3px rgba(45, 212, 191, 0.18);
}

html.dark .nav-btn {
    color: var(--muted-text);
    border-color: transparent;
}

html.dark .nav-btn:hover {
    background-color: rgba(45, 212, 191, 0.12);
    color: var(--primary-accent);
}

html.dark .nav-btn.active {
    background-color: rgba(45, 212, 191, 0.2);
    border-color: rgba(45, 212, 191, 0.45);
    color: var(--primary-accent);
}

.btn-primary,
.btn-secondary,
.btn-tertiary {
    border: none;
    border-radius: 0.75rem;
    cursor: pointer;
    font-weight: 600;
    line-height: 1.2;
    padding: 0.65rem 1.5rem;
    transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

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

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

.btn-secondary {
    background-color: var(--secondary-accent);
    color: #fff;
}

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

.btn-tertiary {
    background-color: transparent;
    border: 2px solid var(--border-color);
    color: var(--muted-text);
}

.btn-tertiary:hover {
    border-color: var(--primary-accent);
    color: var(--primary-accent);
}

.btn-disabled,
.btn-primary:disabled,
.btn-secondary:disabled,
.btn-tertiary:disabled {
    background-color: rgba(148, 163, 184, 0.4);
    color: rgba(255, 255, 255, 0.75);
    cursor: not-allowed;
}

.choice {
    cursor: pointer;
    border: 2px solid var(--border-color);
    border-radius: 1rem;
    transition: border-color 0.2s ease, background-color 0.2s ease, box-shadow 0.2s ease;
    background-color: var(--card-bg);
}

.choice:hover,
.choice.highlight {
    border-color: var(--primary-accent);
    background-color: var(--highlight-soft);
    box-shadow: 0 12px 20px -15px rgba(15, 118, 110, 0.6);
}

.choice.selected {
    border-color: var(--secondary-accent);
    background-color: rgba(249, 115, 22, 0.12);
    box-shadow: 0 12px 20px -15px rgba(249, 115, 22, 0.6);
    font-weight: 600;
}

.choice.correct {
    background-color: var(--success-soft);
    border-color: var(--success);
}

.choice.incorrect {
    background-color: var(--danger-soft);
    border-color: var(--danger);
}

html.dark .choice.correct {
    color: #0f172a;
}

html.dark .choice.incorrect {
    color: #0f172a;
}

.stats-bar {
    background-color: var(--border-color);
    border-radius: 9999px;
    overflow: hidden;
    height: 0.5rem;
}

.stats-bar-fill {
    height: 100%;
    background-image: linear-gradient(90deg, var(--primary-accent), var(--secondary-accent));
    transition: width 0.5s ease-in-out;
}

.mode-tag {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 9999px;
    text-transform: capitalize;
    line-height: 1.2;
}

.mode-study {
    background-color: rgba(15, 118, 110, 0.12);
    color: var(--primary-accent);
}

.mode-quiz {
    background-color: rgba(249, 115, 22, 0.16);
    color: var(--secondary-accent);
}

.mode-assessment {
    background-color: rgba(59, 130, 246, 0.18);
    color: #2563eb;
}

.report-tab {
    border-color: transparent;
    color: var(--muted-text);
    transition: color 0.2s ease, border-color 0.2s ease;
}

.report-tab.active {
    border-color: var(--primary-accent);
    color: var(--primary-accent);
}

.recent-activity-item,
#assessment-list .card {
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.recent-activity-item:hover,
#assessment-list .card:hover {
    border-color: var(--primary-accent);
    box-shadow: 0 18px 35px -25px rgba(15, 118, 110, 0.65);
}

#explanation-box {
    background-color: rgba(15, 118, 110, 0.08) !important;
    border-color: rgba(15, 118, 110, 0.35) !important;
}

html.dark #explanation-box {
    background-color: rgba(45, 212, 191, 0.12) !important;
    border-color: rgba(45, 212, 191, 0.45) !important;
}

#review-list details[open],
#summary-question-list details[open] {
    background-color: var(--highlight-soft);
}

html.dark #review-list details[open],
html.dark #summary-question-list details[open] {
    background-color: rgba(45, 212, 191, 0.18);
}

.completed-section {
    background-color: var(--success-soft) !important;
    color: var(--success);
    font-weight: 600;
}

html.dark .completed-section {
    background-color: rgba(74, 222, 128, 0.2) !important;
    color: var(--success);
}

#review-filters {
    background-color: var(--highlight-soft) !important;
    border-color: var(--border-color) !important;
}

html.dark #review-filters {
    background-color: rgba(45, 212, 191, 0.16) !important;
}

.glossary-term-highlight {
    border-bottom: 2px dotted var(--primary-accent);
    cursor: help;
    color: var(--primary-accent);
    font-weight: 600;
}

#term-popup {
    position: absolute;
    z-index: 100;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    box-shadow: 0 16px 35px -20px rgba(15, 23, 42, 0.55);
    border-radius: 0.75rem;
    padding: 1.25rem;
    max-width: min(24rem, 90vw);
}

#term-popup h4 {
    margin-bottom: 0.5rem;
    font-weight: 700;
    color: var(--primary-accent);
}

.rich-text {
    display: grid;
    gap: 0.75rem;
    font-size: 0.95rem;
    color: inherit;
}

.rich-text p {
    margin: 0;
}

.rich-text ul,
.rich-text ol {
    margin: 0;
    padding-left: 1.25rem;
    display: grid;
    gap: 0.4rem;
}

.rich-text ul {
    list-style: disc;
}

.rich-text ol {
    list-style: decimal;
}

.rich-text strong {
    font-weight: 700;
}

.rich-text em {
    font-style: italic;
}

.rich-text u {
    text-decoration: underline;
    text-decoration-thickness: 2px;
}

.rich-text .rich-text-heading {
    font-weight: 700;
    color: var(--primary-accent);
    margin: 0;
}

.rich-text .rich-text-divider {
    border: none;
    border-top: 2px dashed var(--border-strong);
    margin: 0.5rem 0;
}

.rich-text-note {
    border-radius: 0.75rem;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    background-color: var(--info-soft);
}

.rich-text-note strong {
    display: block;
    margin-bottom: 0.35rem;
}

.rich-text-note-info {
    border-color: #0ea5e9;
    background-color: var(--info-soft);
    color: #0f172a;
}

.rich-text-note-success {
    border-color: var(--success);
    background-color: var(--success-soft);
}

.rich-text-note-warning {
    border-color: var(--warning);
    background-color: var(--warning-soft);
}

.rich-text-note-danger {
    border-color: var(--danger);
    background-color: var(--danger-soft);
}

.rich-text-quote {
    border-inline-start: 4px solid var(--primary-accent);
    margin: 0;
    padding-inline-start: 1rem;
    font-style: italic;
    color: var(--muted-text);
}

.rich-text-list {
    padding-left: 1.25rem;
}

.rich-text-list li::marker {
    color: var(--primary-accent);
    font-weight: 600;
}

html.dark .rich-text-note {
    color: var(--text-color);
}

html.dark .rich-text-quote {
    color: var(--muted-text);
}

.dashboard-stat strong {
    color: var(--primary-accent);
}

.glossary-modal {
    backdrop-filter: blur(6px);
}