:root {
    --bg: #0a1116;
    --surface: rgba(18, 26, 33, 0.92);
    --surface2: rgba(24, 34, 44, 0.9);
    --border: rgba(151, 190, 181, 0.10);
    --border-hover: rgba(181, 156, 255, 0.28);
    --accent: #b59cff;
    --accent2: #58d7ff;
    --accent3: #ff8392;
    --accent4: #ffd56b;
    --text: #e9f0ec;
    --text-muted: #94a59f;
    --muted: #94a59f;
    --code-bg: #111922;
    --green: #7bf0be;
    --orange: #ffbc72;
    --red: #ff8392;
    --nav-h: 64px;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.25);
    --radius: 20px;
    --radius-sm: 14px;
    --nav-accent: var(--accent);
}

body {
    font-family: 'Inter', system-ui, sans-serif;
    background:
        radial-gradient(ellipse 60% 50% at 20% 20%, rgba(181, 156, 255, 0.06), transparent),
        radial-gradient(ellipse 50% 40% at 80% 30%, rgba(88, 215, 255, 0.05), transparent),
        linear-gradient(180deg, #081016 0%, #0b141c 50%, #081015 100%);
    color: var(--text);
    min-height: 100vh;
    padding-top: var(--nav-h);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ── Header ── */
header {
    background: linear-gradient(135deg, rgba(26, 29, 39, 0.9) 0%, rgba(18, 21, 42, 0.9) 100%);
    border-bottom: 1px solid var(--border);
    padding: 24px 32px 0;
    backdrop-filter: blur(16px);
}

.header-top {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 8px;
}

.badge {
    background: var(--accent);
    color: #fff;
    font-size: 11px;
    padding: 3px 10px;
    border-radius: 20px;
    letter-spacing: .5px;
    font-weight: 600;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

header p {
    color: var(--text-muted);
    font-size: .9rem;
    margin-top: 4px;
    margin-bottom: 16px;
}

/* ── Tabs ── */
.tabs {
    display: flex;
    gap: 0;
    border-bottom: none;
    overflow-x: auto;
}

.tab-btn {
    padding: 10px 22px;
    border: none;
    background: transparent;
    color: var(--text-muted);
    font-size: .9rem;
    cursor: pointer;
    border-bottom: 3px solid transparent;
    white-space: nowrap;
    transition: all .2s;
}

.tab-btn:hover {
    color: var(--text);
}

.tab-btn.active {
    color: var(--accent);
    border-bottom-color: var(--accent);
    font-weight: 600;
}

/* ── Content ── */
.tab-content {
    display: none;
    padding: 32px;
    max-width: 960px;
    margin: 0 auto;
}

.tab-content.active {
    display: block;
}

/* ── Cards ── */
.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 24px;
    margin-bottom: 20px;
    backdrop-filter: blur(16px);
    box-shadow: var(--shadow);
    transition: border-color .3s ease, transform .3s cubic-bezier(0.22, 1, 0.36, 1);
}

.card-title {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* ── Priority badges ── */
.priority-red {
    color: var(--red);
}

.priority-orange {
    color: var(--orange);
}

.priority-green {
    color: var(--green);
}

/* ── Lists ── */
ul.styled,
ol.styled {
    padding-left: 0;
    list-style: none;
}

ul.styled li,
ol.styled li {
    padding: 6px 0 6px 20px;
    position: relative;
    color: var(--text-muted);
    font-size: .9rem;
    line-height: 1.6;
}

ul.styled li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent);
}

ol.styled {
    counter-reset: li;
}

ol.styled li {
    counter-increment: li;
}

ol.styled li::before {
    content: counter(li) '.';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

/* ── Code ── */
pre {
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 16px;
    overflow-x: auto;
    font-size: .82rem;
    line-height: 1.7;
    margin: 12px 0;
}

code {
    font-family: 'JetBrains Mono', 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
    color: #a8d8a8;
}

.code-label {
    font-size: .75rem;
    color: var(--accent2);
    font-weight: 600;
    margin: 16px 0 4px;
    letter-spacing: .5px;
    text-transform: uppercase;
}

/* ── Tables ── */
table {
    width: 100%;
    border-collapse: collapse;
    font-size: .88rem;
}

th {
    background: var(--surface2);
    color: var(--accent);
    padding: 10px 14px;
    text-align: left;
    font-weight: 600;
    border-bottom: 2px solid var(--border);
}

td {
    padding: 9px 14px;
    border-bottom: 1px solid var(--border);
    color: var(--text-muted);
}

tr:last-child td {
    border-bottom: none;
}

/* ── Math block ── */
.math {
    background: var(--code-bg);
    border-left: 3px solid var(--accent);
    padding: 12px 16px;
    border-radius: 4px;
    font-size: .9rem;
    margin: 12px 0;
    color: #c9d1d9;
    font-family: 'Cambria Math', Georgia, serif;
}

/* ── Quote ── */
.quote {
    border-left: 3px solid var(--accent2);
    background: rgba(0, 212, 170, .06);
    padding: 14px 18px;
    border-radius: 0 8px 8px 0;
    margin: 14px 0;
    font-style: italic;
    color: var(--text);
    font-size: .9rem;
    line-height: 1.7;
}

/* ── Accordion (mock interview) ── */
.accordion {
    margin-bottom: 12px;
}

.accordion-header {
    background: var(--surface2);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 14px 18px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: .92rem;
    font-weight: 600;
    transition: background .2s;
}

.accordion-header:hover {
    background: #282d45;
}

.accordion-arrow {
    transition: transform .25s;
    color: var(--accent);
}

.accordion.open .accordion-arrow {
    transform: rotate(180deg);
}

.accordion-body {
    display: none;
    background: var(--surface);
    border: 1px solid var(--border);
    border-top: none;
    border-radius: 0 0 8px 8px;
    padding: 18px;
    font-size: .9rem;
    line-height: 1.75;
    color: var(--text-muted);
}

.accordion.open .accordion-body {
    display: block;
}

/* ── Checklist ── */
.check-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
}

.check-item:last-child {
    border-bottom: none;
}

.check-item input[type="checkbox"] {
    margin-top: 3px;
    accent-color: var(--accent);
    width: 16px;
    height: 16px;
    cursor: pointer;
}

.check-item label {
    cursor: pointer;
    font-size: .9rem;
    color: var(--text-muted);
    line-height: 1.5;
}

.check-item input:checked+label {
    text-decoration: line-through;
    color: #4a5278;
}

/* ── Week header ── */
.week-header {
    background: linear-gradient(90deg, var(--accent) 0%, #9c88ff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-size: 1rem;
    font-weight: 700;
    margin: 20px 0 8px;
}

/* ── Progress bar ── */
.progress-wrap {
    background: var(--border);
    border-radius: 4px;
    height: 6px;
    margin: 6px 0 2px;
}

.progress-bar {
    background: var(--accent);
    height: 6px;
    border-radius: 4px;
    transition: width .3s;
}

.progress-label {
    font-size: .75rem;
    color: var(--text-muted);
}

/* ── Tag ── */
.tag {
    display: inline-block;
    background: rgba(108, 99, 255, .18);
    color: var(--accent);
    font-size: .75rem;
    padding: 2px 8px;
    border-radius: 4px;
    margin: 2px 3px;
}

.tag.green {
    background: rgba(0, 212, 170, .12);
    color: var(--accent2);
}

.tag.red {
    background: rgba(244, 67, 54, .12);
    color: #ff7070;
}

.tag.yellow {
    background: rgba(255, 209, 102, .12);
    color: var(--accent4);
}

/* ── Grid ── */
.grid2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

@media (max-width: 660px) {
    .grid2 {
        grid-template-columns: 1fr;
    }

    .tab-btn {
        padding: 10px 14px;
        font-size: .82rem;
    }
}