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

:root {
    --bg: #0f0f0f;
    --card: #1a1a1a;
    --border: #2a2a2a;
    --text: #e0e0e0;
    --muted: #888;
    --accent: #e1306c;
    --accent-dim: rgba(225, 48, 108, 0.15);
    --radius: 8px;
}

html, body {
    background: var(--bg);
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 15px;
    line-height: 1.5;
    min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ===== Layout ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

header {
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    margin-bottom: 2rem;
}

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

header h1 {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.5px;
}

header h1 span { color: var(--accent); }

/* ===== Card ===== */
.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

/* ===== Form ===== */
.form-group { margin-bottom: 1.25rem; }

label {
    display: block;
    font-size: 0.85rem;
    color: var(--muted);
    margin-bottom: 0.4rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

input[type="url"],
input[type="text"],
select {
    width: 100%;
    background: #111;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text);
    padding: 0.6rem 0.9rem;
    font-size: 0.95rem;
    outline: none;
    transition: border-color 0.15s;
}

input[type="url"]:focus,
select:focus {
    border-color: var(--accent);
}

.radio-group {
    display: flex;
    gap: 1rem;
}

.radio-group label {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    text-transform: none;
    letter-spacing: 0;
    font-size: 0.95rem;
    color: var(--text);
    cursor: pointer;
}

.radio-group input[type="radio"] {
    width: auto;
    accent-color: var(--accent);
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.6rem 1.25rem;
    border-radius: var(--radius);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: opacity 0.15s, background 0.15s;
}

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

.btn-primary:hover { opacity: 0.85; }

.btn-secondary {
    background: var(--card);
    color: var(--text);
    border: 1px solid var(--border);
}

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

.btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* ===== Alerts ===== */
.alert {
    padding: 0.75rem 1rem;
    border-radius: var(--radius);
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.alert-error {
    background: rgba(225, 48, 108, 0.12);
    border: 1px solid rgba(225, 48, 108, 0.4);
    color: #f87171;
}

/* ===== Session info bar ===== */
.session-info {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem 2rem;
    align-items: baseline;
}

.session-info .title {
    font-size: 1.1rem;
    font-weight: 700;
    flex: 1 1 100%;
}

.meta-item {
    font-size: 0.82rem;
    color: var(--muted);
}

.meta-item strong { color: var(--text); }

/* ===== Mode tabs ===== */
.mode-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.mode-tab {
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--muted);
    cursor: pointer;
    text-decoration: none;
    transition: all 0.15s;
}

.mode-tab.active,
.mode-tab:hover {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
}

/* ===== Analysis controls ===== */
.analyze-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
}

.threshold-wrap {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

.threshold-wrap input[type="range"] {
    width: 140px;
    accent-color: var(--accent);
}

#threshold-value {
    min-width: 2.5ch;
    text-align: right;
    font-weight: 700;
    color: var(--accent);
}

/* ===== Frame grid ===== */
.section-heading {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--muted);
    margin-bottom: 0.75rem;
    margin-top: 1.5rem;
}

.frame-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 6px;
}

.frame-item {
    position: relative;
    cursor: pointer;
    border-radius: 4px;
    overflow: hidden;
    background: #111;
    aspect-ratio: 9/16;
}

.frame-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: opacity 0.15s;
}

.frame-item:hover img { opacity: 0.75; }

.frame-number {
    position: absolute;
    bottom: 3px;
    right: 4px;
    font-size: 0.65rem;
    color: rgba(255,255,255,0.7);
    background: rgba(0,0,0,0.6);
    padding: 1px 4px;
    border-radius: 3px;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.15s;
}

.frame-item:hover .frame-number { opacity: 1; }

/* Flagged frame styles */
.frame-item.flagged {
    box-shadow: 0 0 0 2px var(--accent), 0 0 12px var(--accent-dim);
}

.frame-score {
    position: absolute;
    top: 3px;
    left: 4px;
    font-size: 0.6rem;
    font-weight: 700;
    color: #fff;
    background: var(--accent);
    padding: 1px 4px;
    border-radius: 3px;
    pointer-events: none;
}

/* ===== Lightbox ===== */
.lightbox-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.92);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
}

.lightbox-overlay.hidden { display: none; }

.lightbox-img-wrap {
    position: relative;
    max-width: 100%;
    max-height: calc(100vh - 120px);
    display: flex;
    align-items: center;
    justify-content: center;
}

.lightbox-img-wrap img {
    max-width: 100%;
    max-height: calc(100vh - 120px);
    object-fit: contain;
    border-radius: 4px;
    display: block;
}

.lightbox-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(0,0,0,0.6);
    border: none;
    color: #fff;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.75rem 1rem;
    border-radius: 4px;
    line-height: 1;
    transition: background 0.15s;
}

.lightbox-nav:hover { background: rgba(255,255,255,0.15); }
.lightbox-nav.prev { left: -3.5rem; }
.lightbox-nav.next { right: -3.5rem; }

.lightbox-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.lightbox-caption {
    font-size: 0.85rem;
    color: var(--muted);
}

.lightbox-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    color: var(--muted);
    font-size: 1.5rem;
    cursor: pointer;
    line-height: 1;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
}

.lightbox-close:hover { color: var(--text); background: var(--border); }

/* ===== Processing spinner ===== */
.spinner {
    display: inline-block;
    width: 14px;
    height: 14px;
    border: 2px solid rgba(255,255,255,0.3);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
    vertical-align: middle;
}

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

/* ===== Responsive ===== */
@media (max-width: 600px) {
    .frame-grid { grid-template-columns: repeat(auto-fill, minmax(90px, 1fr)); }
    .lightbox-nav.prev { left: -2rem; }
    .lightbox-nav.next { right: -2rem; }
    .session-info { gap: 0.5rem 1rem; }
}