/* ============================================================
   Next Chapter Phase I — Lab Journal Stylesheet
   Original styles preserved, plus new image/gif gallery section.
   ============================================================ */

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --bg: #f7f5f2;
    --surface: #ffffff;
    --border: #e5e2dd;
    --text: #1a1916;
    --muted: #8a8780;
    --accent: #2a5c8f;
    --accent-light: #e8f0f8;
}

body {
    font-family: 'DM Sans', sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
}

header {
    padding: 3rem 2rem 2rem;
    max-width: 960px;
    margin: 0 auto;
    border-bottom: 1px solid var(--border);
}

.eyebrow {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 0.75rem;
}

h1 {
    font-family: 'DM Serif Display', serif;
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 400;
    line-height: 1.15;
    color: var(--text);
    margin-bottom: 0.75rem;
}

.subtitle {
    font-size: 15px;
    color: var(--muted);
    font-weight: 300;
    max-width: 480px;
    line-height: 1.6;
}

main {
    max-width: 960px;
    margin: 0 auto;
    padding: 2rem;
}

.week { margin-bottom: 3rem; }

.week-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.25rem;
}

.week-label {
    font-family: 'DM Serif Display', serif;
    font-size: 1.3rem;
    font-weight: 400;
    color: var(--text);
    white-space: nowrap;
}

.week-line {
    flex: 1;
    height: 1px;
    background: var(--border);
}

.day-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1rem;
}


/* ── DAY CARD ── */
.day-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    overflow: hidden;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.day-card.has-content:hover {
    border-color: var(--accent);
    box-shadow: 0 4px 16px rgba(42, 92, 143, 0.08);
}

.day-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.875rem 1rem;
    cursor: pointer;
    user-select: none;
}

.day-card:not(.has-content) .day-card-header {
    cursor: default;
}

.day-tag {
    font-size: 12px;
    font-weight: 500;
    color: var(--accent);
    background: var(--accent-light);
    padding: 3px 10px;
    border-radius: 20px;
}

.expand-icon {
    font-size: 18px;
    color: var(--muted);
    transition: transform 0.3s ease;
    line-height: 1;
}

.day-card.open .expand-icon {
    transform: rotate(45deg);
}


/* ── EMBED PANEL ── */
.embed-panel {
    display: none;
    border-top: 1px solid var(--border);
    background: var(--bg);
}

.day-card.open .embed-panel {
    display: block;
}


/* ── PLACEHOLDER ── */
.placeholder {
    padding: 1.5rem;
    text-align: center;
    font-size: 13px;
    color: var(--muted);
    border-top: 1px solid var(--border);
}


/* ── VIDEO LIST ── */
.video-list {
    padding: 0.75rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.video-item {
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    background: var(--surface);
}

.video-item-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 0.875rem;
    cursor: pointer;
    user-select: none;
}

.video-item-header:hover {
    background: var(--accent-light);
}

.video-number {
    font-size: 11px;
    font-weight: 500;
    color: var(--muted);
    min-width: 18px;
}

.video-title {
    font-size: 13px;
    color: var(--text);
    flex: 1;
}

.video-arrow {
    font-size: 11px;
    color: var(--muted);
    transition: transform 0.25s ease;
}

.video-item.open .video-arrow {
    transform: rotate(90deg);
}

.video-player {
    display: none;
    padding: 0.75rem;
    border-top: 1px solid var(--border);
    background: #000;
}

.video-item.open .video-player {
    display: block;
}

.video-player video {
    width: 100%;
    border-radius: 4px;
    display: block;
    max-height: 240px;
}


/* ── PDF SECTION ── */
.pdf-section {
    padding: 0.75rem;
    border-top: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.pdf-section-label {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: #7c3aed;
    padding: 0 0.25rem;
    margin-bottom: 0.25rem;
}

.pdf-item {
    border: 1px solid #ddd5f5;
    border-radius: 8px;
    overflow: hidden;
    background: var(--surface);
}

.pdf-item-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 0.875rem;
    cursor: pointer;
    user-select: none;
}

.pdf-item-header:hover {
    background: #f3eeff;
}

.pdf-icon { font-size: 14px; }

.pdf-title {
    font-size: 13px;
    color: var(--text);
    flex: 1;
}

.pdf-arrow {
    font-size: 11px;
    color: #7c3aed;
    transition: transform 0.25s ease;
}

.pdf-item.open .pdf-arrow {
    transform: rotate(90deg);
}

.pdf-viewer {
    display: none;
    border-top: 1px solid #ddd5f5;
}

.pdf-item.open .pdf-viewer {
    display: block;
}

.pdf-viewer iframe {
    width: 100%;
    height: 500px;
    border: none;
    display: block;
}


/* ============================================================
   NEW: IMAGE / GIF GALLERY SECTION
   For showing project screenshots, demo gifs, or annotated
   walkthroughs of lab work. Color theme: warm coral to keep
   it visually distinct from videos (blue) and PDFs (purple).
   ============================================================ */

.image-section {
    padding: 0.75rem;
    border-top: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.image-section-label {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: #c2410c;
    padding: 0 0.25rem;
    margin-bottom: 0.25rem;
}

.image-item {
    border: 1px solid #fed7aa;
    border-radius: 8px;
    overflow: hidden;
    background: var(--surface);
}

.image-item-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 0.875rem;
    cursor: pointer;
    user-select: none;
}

.image-item-header:hover {
    background: #fff7ed;
}

.image-icon { font-size: 14px; }

.image-title {
    font-size: 13px;
    color: var(--text);
    flex: 1;
}

.image-arrow {
    font-size: 11px;
    color: #c2410c;
    transition: transform 0.25s ease;
}

.image-item.open .image-arrow {
    transform: rotate(90deg);
}

.image-viewer {
    display: none;
    padding: 0.75rem;
    border-top: 1px solid #fed7aa;
    background: #fafaf9;
}

.image-item.open .image-viewer {
    display: block;
}

.image-viewer img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.image-caption {
    font-size: 12px;
    color: var(--muted);
    margin-top: 0.5rem;
    line-height: 1.5;
    font-style: italic;
}


/* ── FOOTER ── */
footer {
    text-align: center;
    padding: 2rem;
    font-size: 12px;
    color: var(--muted);
    border-top: 1px solid var(--border);
    max-width: 960px;
    margin: 0 auto;
}