/* === STUDY TRACKER — Mobile‑First Retro Y2K (Kami System) === */

:root {
    --brand: #1B365D;
    --brand-light: #2D5A8A;
    --parchment: #f5f4ed;
    --ivory: #faf9f5;
    --warm-sand: #e8e6dc;
    --dark-surface: #30302e;
    --near-black: #141413;
    --dark-warm: #3d3d3a;
    --olive: #504e49;
    --stone: #6b6a64;
    --border: #e8e6dc;
    --border-soft: #e5e3d8;
    --tag-fill: #E4ECF5;
    --serif: Charter, Georgia, "Times New Roman", serif;
    --sans: var(--serif);
    --mono: "Courier New", "JetBrains Mono", "SF Mono", "Fira Code", Consolas, Monaco, monospace;
    --radius-pixel: 2px;
    --radius-card: 4px;
    --border-width: 2px;
    --anim-fast: 100ms;
    --anim-default: 150ms;
    --anim-enter: 200ms;
    --anim-cross: 300ms;
}

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

body {
    background-color: var(--parchment);
    color: var(--near-black);
    font-family: var(--serif);
    font-size: 14px;
    line-height: 1.55;
    font-weight: 400;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.04'/%3E%3C/svg%3E");
    min-height: 100vh;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 40px 16px 60px;
}

.section {
    margin-bottom: 48px;
}

.section-head {
    margin-bottom: 20px;
}

.section-num {
    font-family: var(--serif);
    font-weight: 500;
    font-size: 13px;
    line-height: 1.2;
    letter-spacing: 0.4px;
    color: var(--brand);
    margin-bottom: 6px;
    font-variant-numeric: tabular-nums;
}

.hero-title {
    font-family: var(--serif);
    font-weight: 500;
    font-size: 42px;
    line-height: 1.1;
    letter-spacing: -0.8px;
    color: var(--near-black);
    margin-bottom: 12px;
    word-break: break-word;
}

.section-title {
    font-family: var(--serif);
    font-weight: 500;
    font-size: 26px;
    line-height: 1.2;
    letter-spacing: 0.3px;
    color: var(--near-black);
}

.section-lede {
    font-family: var(--serif);
    font-weight: 500;
    font-size: 15px;
    line-height: 1.5;
    color: var(--olive);
    max-width: 90%;
}

.retro-line {
    display: block;
    margin: 12px 0 16px;
    width: 100px;
    height: auto;
}

.card {
    background: var(--ivory);
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-card);
    padding: 24px;
    box-shadow: 0 0 0 0 transparent;
    transition: box-shadow var(--anim-default) cubic-bezier(0.2, 0, 0, 1);
}

.card:hover {
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.05);
}

.timer-card {
    text-align: center;
    position: relative;
}

.timer-display {
    font-family: var(--mono);
    font-size: 64px;
    font-weight: 400;
    line-height: 1.1;
    letter-spacing: 4px;
    color: var(--near-black);
    background: var(--parchment);
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-pixel);
    padding: 16px 0;
    margin-bottom: 16px;
    font-variant-numeric: tabular-nums;
    box-shadow: inset 2px 2px 0 rgba(0, 0, 0, 0.05);
    transition: color var(--anim-fast) ease;
}

.timer-progress {
    width: 80px;
    height: 80px;
    margin: 0 auto 16px;
    display: block;
}

.timer-track {
    opacity: 0.3;
}

.timer-fill {
    transition: stroke-dashoffset var(--anim-cross) cubic-bezier(0.2, 0, 0, 1);
    will-change: stroke-dashoffset;
}

.timer-controls {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin-bottom: 20px;
}

.duration-options {
    display: flex;
    gap: 8px;
    justify-content: center;
}

.btn-retro {
    font-family: var(--serif);
    font-weight: 500;
    font-size: 13px;
    line-height: 1;
    padding: 10px 18px;
    background: var(--warm-sand);
    color: var(--dark-warm);
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-pixel);
    box-shadow: 2px 2px 0 rgba(0, 0, 0, 0.1);
    cursor: pointer;
    text-transform: uppercase;
    letter-spacing: 0.4px;
    transition: transform var(--anim-fast) cubic-bezier(0.2, 0, 0, 1),
        background-color var(--anim-fast) cubic-bezier(0.2, 0, 0, 1),
        box-shadow var(--anim-fast) cubic-bezier(0.2, 0, 0, 1);
    display: inline-flex;
    align-items: center;
    gap: 6px;
    user-select: none;
}

.btn-retro:active {
    transform: scale(0.96);
    box-shadow: inset 1px 1px 0 rgba(0, 0, 0, 0.2);
}

.btn-retro.small {
    padding: 8px 14px;
    font-size: 12px;
    min-width: 44px;
    justify-content: center;
}

.btn-retro.active {
    background: var(--brand);
    color: var(--ivory);
    border-color: var(--brand);
    box-shadow: 2px 2px 0 rgba(0, 0, 0, 0.2);
}

.ambient-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 12px;
}

.ambient-btn {
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 16px 10px;
    font-size: 12px;
    transition: background-color var(--anim-fast) cubic-bezier(0.2, 0, 0, 1),
        transform var(--anim-fast) cubic-bezier(0.2, 0, 0, 1);
}

.ambient-btn[aria-pressed="true"] {
    background: var(--brand);
    color: var(--ivory);
    border-color: var(--brand);
}

.ambient-svg {
    display: block;
}

.ambient-label {
    text-transform: none;
    font-weight: 500;
}

.ambient-status {
    font-size: 10px;
    color: var(--olive);
    min-height: 1.2em;
}

.session-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.session-item {
    background: var(--ivory);
    border: var(--border-width) solid var(--border);
    border-radius: var(--radius-card);
    padding: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    animation: sessionEnter var(--anim-enter) cubic-bezier(0.2, 0, 0, 1);
    transition: box-shadow var(--anim-default) cubic-bezier(0.2, 0, 0, 1);
}

.session-item:hover {
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.05);
}

@keyframes sessionEnter {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.session-subject {
    font-family: var(--serif);
    font-weight: 500;
    font-size: 15px;
    line-height: 1.3;
    color: var(--near-black);
}

.session-meta {
    font-family: var(--serif);
    font-size: 12px;
    color: var(--stone);
    display: flex;
    gap: 8px;
    align-items: center;
}

.session-duration {
    font-family: var(--sans);
    font-weight: 500;
    font-size: 12px;
    color: var(--brand);
    background: var(--tag-fill);
    padding: 3px 10px;
    border-radius: 2px;
    letter-spacing: 0.3px;
}

.empty-state {
    text-align: center;
    padding: 36px;
}

.olive-text {
    color: var(--olive);
}

.stone-text {
    color: var(--stone);
    font-size: 12px;
}

.brand-text {
    color: var(--brand);
    font-weight: 500;
}

.meta-footer {
    margin-top: 48px;
    border-top: var(--border-width) solid var(--border-soft);
    padding-top: 20px;
    text-align: center;
}

@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    .session-item {
        animation: none;
    }

    .timer-fill {
        transition: none;
    }
}

@media (min-width: 768px) {
    .container {
        max-width: 720px;
        padding: 60px 32px 80px;
    }

    .hero-title {
        font-size: 72px;
        letter-spacing: -1px;
    }

    .section-title {
        font-size: 32px;
    }

    .timer-display {
        font-size: 80px;
    }

    .ambient-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 1024px) {
    .container {
        max-width: 800px;
    }

    .hero-title {
        font-size: 88px;
    }
}

.meta-footer {
    margin-top: 48px;
    border-top: var(--border-width) solid var(--border-soft);
    padding-top: 16px;
    text-align: center;
}

.footer-row {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.footer-clock {
    font-family: var(--mono);
    font-size: 13px;
    color: var(--dark-warm);
    font-variant-numeric: tabular-nums;
    letter-spacing: 1px;
    background: var(--warm-sand);
    padding: 4px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-pixel);
    display: inline-block;
}

.footer-separator {
    color: var(--border);
    font-size: 13px;
}

.footer-count {
    font-family: var(--serif);
    font-size: 12px;
    color: var(--stone);
    letter-spacing: 0.3px;
}

@media print {
    body {
        background-image: none;
    }

    @page {
        size: A4;
        margin: 14mm 16mm;
        background: var(--parchment);
    }

    .card,
    .session-item {
        break-inside: avoid;
    }
}