/* ── Reset & Base ─────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --bg: #0f1117;
    --bg-card: #181b24;
    --bg-card-hover: #1e2230;
    --border: #2a2e3b;
    --text: #e8eaf0;
    --text-dim: #8b90a0;
    --text-muted: #5a5f72;
    --accent: #6c5ce7;
    --accent-glow: rgba(108, 92, 231, 0.3);
    --green: #27ae60;
    --green-soft: rgba(39, 174, 96, 0.15);
    --blue: #2980b9;
    --blue-soft: rgba(41, 128, 185, 0.15);
    --purple: #8e44ad;
    --purple-soft: rgba(142, 68, 173, 0.15);
    --gold: #f1c40f;
    --gold-soft: rgba(241, 196, 15, 0.15);
    --red: #e74c3c;
    --red-soft: rgba(231, 76, 60, 0.15);
    --orange: #e67e22;
    --radius: 16px;
    --radius-sm: 10px;
    --shadow: 0 4px 24px rgba(0,0,0,0.3);
    --shadow-lg: 0 8px 40px rgba(0,0,0,0.4);
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

.hidden { display: none !important; }

/* ── Loading ─────────────────────────────────────────────────── */
#loading-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}

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

.loader-ring {
    width: 56px; height: 56px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto 1rem;
}

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

.loader-text {
    color: var(--text-dim);
    font-size: 0.95rem;
}

/* ── Error ────────────────────────────────────────────────────── */
#error-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}

.error-wrap {
    text-align: center;
    max-width: 400px;
}

.error-icon { font-size: 3rem; display: block; margin-bottom: 1rem; }
.error-wrap h2 { margin-bottom: 0.5rem; }
.error-wrap p { color: var(--text-dim); margin-bottom: 1.5rem; }

.retry-btn {
    background: var(--accent);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.15s, box-shadow 0.15s;
}
.retry-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px var(--accent-glow);
}

/* ── Dashboard Layout ─────────────────────────────────────────── */
#dashboard {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem 4rem;
}

/* ── Header ───────────────────────────────────────────────────── */
.dash-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 2.5rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo-mark {
    width: 52px; height: 52px;
    background: linear-gradient(135deg, var(--accent), #a29bfe);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    box-shadow: 0 4px 16px var(--accent-glow);
}

.header-title {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.header-sub {
    color: var(--text-dim);
    font-size: 0.875rem;
    margin-top: 2px;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.streak-badge {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 0.5rem 1rem;
    border-radius: 100px;
}

.streak-flame { font-size: 1.2rem; }
.streak-num { font-weight: 700; font-size: 1.1rem; }
.streak-label { color: var(--text-dim); font-size: 0.8rem; }

.last-active {
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* ── Hero Stats ───────────────────────────────────────────────── */
.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.25rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.stat-ring-wrap {
    position: relative;
    width: 100px; height: 100px;
    margin: 0 auto 0.75rem;
}

.stat-ring { width: 100%; height: 100%; transform: rotate(-90deg); }

.ring-bg {
    fill: none;
    stroke: var(--border);
    stroke-width: 8;
}

.ring-fill {
    fill: none;
    stroke: var(--accent);
    stroke-width: 8;
    stroke-linecap: round;
    stroke-dasharray: 326.73;
    stroke-dashoffset: 326.73;
    transition: stroke-dashoffset 1.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.ring-center {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.ring-pct {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
}

.stat-big {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.stat-label {
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.stat-detail {
    color: var(--text-dim);
    font-size: 0.8rem;
}

.stat-score .stat-big { color: var(--green); }
.stat-days .stat-big { color: var(--blue); }
.stat-achievements .stat-big { color: var(--gold); }

/* ── Section Titles ───────────────────────────────────────────── */
.section-title {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.35rem;
    font-weight: 700;
    margin-bottom: 1.25rem;
    letter-spacing: -0.01em;
}

/* ── Topic Cards ──────────────────────────────────────────────── */
.topics-section { margin-bottom: 3rem; }

.topics-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
}

.topic-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    position: relative;
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s;
}

.topic-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.topic-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
}

.topic-card[data-color="green"]::before { background: var(--green); }
.topic-card[data-color="blue"]::before { background: var(--blue); }
.topic-card[data-color="purple"]::before { background: var(--purple); }

.topic-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.topic-name {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.05rem;
}

.topic-icon { font-size: 1.3rem; }

.topic-badge {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.2rem 0.6rem;
    border-radius: 100px;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.badge-active {
    background: var(--green-soft);
    color: var(--green);
}

.badge-upcoming {
    background: rgba(139, 144, 160, 0.15);
    color: var(--text-dim);
}

.badge-complete {
    background: var(--gold-soft);
    color: var(--gold);
}

.topic-progress-bar {
    width: 100%;
    height: 8px;
    background: var(--border);
    border-radius: 100px;
    margin-bottom: 0.75rem;
    overflow: hidden;
}

.topic-progress-fill {
    height: 100%;
    border-radius: 100px;
    transition: width 1.2s cubic-bezier(0.4, 0, 0.2, 1);
    width: 0%;
}

.topic-card[data-color="green"] .topic-progress-fill { background: var(--green); }
.topic-card[data-color="blue"] .topic-progress-fill { background: var(--blue); }
.topic-card[data-color="purple"] .topic-progress-fill { background: var(--purple); }

.topic-stats {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: var(--text-dim);
    margin-bottom: 0.75rem;
}

.topic-next {
    font-size: 0.82rem;
    color: var(--text-dim);
    border-top: 1px solid var(--border);
    padding-top: 0.75rem;
}

.topic-next strong { color: var(--text); font-weight: 600; }

/* ── Score Chart ──────────────────────────────────────────────── */
.timeline-section { margin-bottom: 3rem; }

.chart-container {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    height: 300px;
    position: relative;
}

#score-chart {
    width: 100%;
    height: 100%;
}

.score-legend {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    margin-top: 0.75rem;
    font-size: 0.8rem;
    color: var(--text-dim);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.legend-dot {
    width: 10px; height: 10px;
    border-radius: 50%;
    display: inline-block;
}

.legend-dot.quiz { background: var(--blue); }
.legend-dot.final { background: var(--green); }

.legend-line.mastery {
    width: 20px;
    height: 2px;
    background: var(--red);
    display: inline-block;
    opacity: 0.6;
}

/* ── History Table ────────────────────────────────────────────── */
.history-section { margin-bottom: 3rem; }

.table-wrap {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
}

.history-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.history-table thead {
    background: rgba(108, 92, 231, 0.08);
}

.history-table th {
    padding: 0.9rem 1.25rem;
    text-align: left;
    font-weight: 600;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-dim);
    border-bottom: 1px solid var(--border);
}

.history-table td {
    padding: 0.85rem 1.25rem;
    border-bottom: 1px solid var(--border);
}

.history-table tbody tr:last-child td {
    border-bottom: none;
}

.history-table tbody tr {
    transition: background 0.15s;
}

.history-table tbody tr:hover {
    background: var(--bg-card-hover);
}

.score-pill {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    border-radius: 6px;
    font-weight: 600;
    font-size: 0.85rem;
    min-width: 48px;
    text-align: center;
}

.score-high { background: var(--green-soft); color: var(--green); }
.score-mid { background: var(--gold-soft); color: var(--orange); }
.score-low { background: var(--red-soft); color: var(--red); }

.status-pass {
    color: var(--green);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.lesson-topic-icon {
    margin-right: 0.4rem;
}

/* ── Achievements ─────────────────────────────────────────────── */
.achievements-section { margin-bottom: 3rem; }

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 1rem;
}

.achievement-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 1.25rem;
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    transition: transform 0.2s, box-shadow 0.2s;
}

.achievement-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.achievement-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.achievement-info h4 {
    font-weight: 700;
    font-size: 0.9rem;
    margin-bottom: 0.2rem;
}

.achievement-info p {
    color: var(--text-dim);
    font-size: 0.78rem;
}

.achievement-date {
    color: var(--text-muted);
    font-size: 0.72rem;
    margin-top: 0.3rem;
}

/* ── Pace Tracker ─────────────────────────────────────────────── */
.pace-section { margin-bottom: 3rem; }

.pace-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
}

.pace-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
}

.pace-status {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.pace-status.on-track { color: var(--green); }
.pace-status.behind { color: var(--orange); }
.pace-status.at-risk { color: var(--red); }
.pace-status.ahead { color: var(--blue); }

.pace-detail {
    color: var(--text-dim);
    font-size: 0.85rem;
    line-height: 1.6;
}

.pace-card-title {
    font-weight: 700;
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.milestone-list {
    list-style: none;
}

.milestone-list li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border);
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.milestone-list li:last-child { border-bottom: none; }

.milestone-icon {
    font-size: 1.1rem;
    flex-shrink: 0;
}

.milestone-done {
    color: var(--text-muted);
    text-decoration: line-through;
}

.powerups-grid {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.powerup-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(108, 92, 231, 0.08);
    padding: 0.5rem 0.9rem;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
}

.powerup-icon { font-size: 1.2rem; }
.powerup-count { font-weight: 700; color: var(--accent); }

/* ── Footer ───────────────────────────────────────────────────── */
.dash-footer {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.8rem;
}

.footer-note { margin-top: 0.25rem; }

/* ── Responsive ───────────────────────────────────────────────── */
@media (max-width: 1024px) {
    .hero-stats { grid-template-columns: repeat(2, 1fr); }
    .topics-grid { grid-template-columns: repeat(2, 1fr); }
    .pace-grid { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
    #dashboard { padding: 1rem 1rem 3rem; }
    .hero-stats { grid-template-columns: 1fr; }
    .topics-grid { grid-template-columns: 1fr; }
    .dash-header { flex-direction: column; align-items: flex-start; }
    .header-right { flex-direction: column; align-items: flex-start; gap: 0.5rem; }
    .header-title { font-size: 1.4rem; }
    .history-table { font-size: 0.8rem; }
    .history-table th, .history-table td { padding: 0.6rem 0.75rem; }
}

/* ── Animations ───────────────────────────────────────────────── */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(16px); }
    to { opacity: 1; transform: translateY(0); }
}

.animate-in {
    animation: fadeInUp 0.5s ease forwards;
    opacity: 0;
}

.animate-in:nth-child(1) { animation-delay: 0.05s; }
.animate-in:nth-child(2) { animation-delay: 0.1s; }
.animate-in:nth-child(3) { animation-delay: 0.15s; }
.animate-in:nth-child(4) { animation-delay: 0.2s; }

/* ── No Data State ────────────────────────────────────────────── */
.no-data {
    text-align: center;
    padding: 2rem;
    color: var(--text-dim);
    font-size: 0.9rem;
}