acht-damen-tuerme-problem/app/static/css/index.css

:root {
    --bg: #f4efe7;
    --bg-accent: #efe3cd;
    --surface: rgba(255, 250, 242, 0.82);
    --surface-strong: #fffaf2;
    --text: #1e1f1d;
    --muted: #5f615c;
    --navy: #1f3140;
    --navy-soft: #324d63;
    --gold: #c68b2c;
    --gold-soft: #e7bf77;
    --line: rgba(31, 49, 64, 0.12);
    --shadow: 0 24px 60px rgba(37, 42, 48, 0.14);
}

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

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    color: var(--text);
    font-family: Georgia, "Times New Roman", serif;
    background:
        radial-gradient(circle at top left, rgba(255, 255, 255, 0.9), transparent 24%),
        radial-gradient(circle at 82% 18%, rgba(198, 139, 44, 0.2), transparent 20%),
        linear-gradient(180deg, #f7f0e5 0%, #efe5d5 52%, #f4efe7 100%);
}

a {
    color: inherit;
    text-decoration: none;
}

main {
    width: min(1200px, calc(100vw - 32px));
    margin: 0 auto;
    padding: 34px 0 56px;
}

.landing-nav {
    width: 100%;
    margin: 0;
    padding: 18px max(16px, calc((100vw - 1200px) / 2)) 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    position: sticky;
    top: 0;
    z-index: 20;
    border-top: 0;
    border-right: 4px solid #12212d;
    border-bottom: 4px solid #12212d;
    border-left: 4px solid #12212d;
    background:
        linear-gradient(180deg, rgba(17, 29, 39, 0.96), rgba(31, 49, 64, 0.94));
    backdrop-filter: blur(12px);
    box-shadow: 0 18px 40px rgba(31, 49, 64, 0.18);
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    color: #fff7eb;
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 0.03em;
}

.brand-mark {
    width: 40px;
    height: 40px;
    display: grid;
    place-items: center;
    border-radius: 8px;
    background: linear-gradient(135deg, var(--gold), var(--gold-soft));
    color: #2c2215;
    font-size: 22px;
}

.landing-links {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 14px;
    color: #ecf4fb;
}

.landing-links a:not(.nav-cta) {
    padding: 12px 14px;
    border: 2px solid transparent;
    background: rgba(255, 255, 255, 0.04);
    opacity: 0.92;
}

.landing-links a:not(.nav-cta):hover {
    opacity: 1;
    border-color: rgba(231, 191, 119, 0.45);
}

.lang-switch,
.nav-cta,
.hero-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 13px 20px;
    font-weight: 700;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.lang-switch {
    min-width: 68px;
    border: 2px solid rgba(231, 191, 119, 0.45);
    background: rgba(255, 255, 255, 0.06);
    color: #fff7eb;
    cursor: pointer;
    font-family: inherit;
}

.nav-cta {
    background: linear-gradient(135deg, var(--gold), var(--gold-soft));
    color: #2d2418;
}

.nav-cta.secondary {
    background: rgba(255, 255, 255, 0.08);
    color: #f8fafc;
    border: 1px solid rgba(255, 255, 255, 0.16);
}

.lang-switch:hover,
.nav-cta:hover,
.hero-button:hover {
    transform: translateY(-2px);
}

.hero {
    padding: 88px 0 56px;
    display: grid;
    grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
    gap: 42px;
    align-items: center;
}

.eyebrow {
    margin: 0 0 12px;
    color: var(--navy-soft);
    text-transform: uppercase;
    letter-spacing: 0.14em;
    font-size: 13px;
    font-weight: 700;
}

.hero h1,
.info-band h2,
.section-heading h2,
.cta-panel h2 {
    margin: 0;
    line-height: 0.95;
    letter-spacing: -0.03em;
    font-size: clamp(2.8rem, 5vw, 5.5rem);
    color: #182029;
}

.hero-text,
.info-band p,
.feature-card p,
.journey-step p,
.cta-panel p {
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    font-size: 18px;
    line-height: 1.7;
    color: var(--muted);
}

.hero-text {
    max-width: 640px;
    margin: 24px 0 0;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 30px;
}

.hero-button.primary {
    background: linear-gradient(135deg, var(--navy), var(--navy-soft));
    color: #f9fbfd;
    box-shadow: 0 14px 30px rgba(31, 49, 64, 0.22);
}

.hero-button.secondary {
    border: 1px solid rgba(31, 49, 64, 0.16);
    background: rgba(255, 255, 255, 0.5);
    color: var(--navy);
}

.hero-facts {
    margin-top: 30px;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
}

.hero-facts article {
    padding: 18px;
    border-radius: 10px;
    background: rgba(255, 250, 242, 0.65);
    border: 1px solid rgba(31, 49, 64, 0.08);
    box-shadow: var(--shadow);
}

.hero-facts strong {
    display: block;
    font-size: 18px;
    color: var(--navy);
}

.hero-facts span {
    display: block;
    margin-top: 6px;
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    color: var(--muted);
    line-height: 1.5;
}

.hero-visual {
    position: relative;
    min-height: 620px;
    display: grid;
    place-items: center;
}

.board-showcase {
    width: min(100%, 520px);
    aspect-ratio: 1;
    padding: 18px;
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    gap: 0;
    border-radius: 14px;
    background:
        linear-gradient(145deg, rgba(255, 255, 255, 0.85), rgba(247, 233, 210, 0.7)),
        rgba(255, 255, 255, 0.5);
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
}

.board-cell {
    position: relative;
    display: grid;
    place-items: center;
    font-size: clamp(20px, 2vw, 30px);
    transition: transform 0.45s ease, opacity 0.45s ease, background 0.45s ease;
}

.board-cell.light {
    background: #f7e6ca;
}

.board-cell.dark {
    background: #92613a;
}

.board-cell.highlight {
    background: #2f485f;
}

.board-cell.queen::after {
    content: "♛";
    color: #fff3df;
    text-shadow: 0 8px 18px rgba(0, 0, 0, 0.28);
    transform: scale(1);
    animation: queenPulse 1.8s ease-in-out infinite;
}

.floating-card {
    position: absolute;
    padding: 16px 18px;
    border-radius: 8px;
    background: rgba(255, 250, 242, 0.85);
    border: 1px solid rgba(31, 49, 64, 0.08);
    box-shadow: 0 18px 35px rgba(31, 49, 64, 0.14);
    backdrop-filter: blur(10px);
}

.solver-card {
    top: 26px;
    right: -8px;
}

.timer-card {
    left: -8px;
    bottom: 34px;
}

.floating-label {
    margin: 0;
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--muted);
}

.floating-value {
    margin: 6px 0 0;
    font-size: 22px;
    color: var(--navy);
}

.info-band,
.feature-section,
.journey-section,
.cta-section {
    padding: 38px 0;
}

.info-band-inner,
.cta-panel {
    padding: 36px;
    border-radius: 12px;
    background: linear-gradient(135deg, rgba(255, 250, 242, 0.88), rgba(245, 230, 205, 0.7));
    border: 1px solid rgba(31, 49, 64, 0.08);
    box-shadow: var(--shadow);
}

.info-band h2 {
    font-size: clamp(2.2rem, 4vw, 4.2rem);
    margin-bottom: 18px;
}

.section-heading {
    max-width: 760px;
    margin-bottom: 28px;
}

.section-heading h2 {
    font-size: clamp(2.2rem, 3.8vw, 4rem);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
}

.feature-card,
.journey-step {
    padding: 26px;
    border-radius: 10px;
    background: rgba(255, 250, 242, 0.72);
    border: 1px solid rgba(31, 49, 64, 0.08);
    box-shadow: var(--shadow);
}

.feature-icon {
    display: inline-grid;
    place-items: center;
    width: 54px;
    height: 54px;
    border-radius: 8px;
    background: linear-gradient(135deg, var(--navy), var(--navy-soft));
    color: #fff3df;
    font-size: 28px;
}

.feature-card h3,
.journey-step h3 {
    margin: 18px 0 10px;
    font-size: 28px;
    color: #1c2833;
}

.journey-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
}

.step-number {
    display: inline-block;
    margin-bottom: 18px;
    color: var(--gold);
    font-size: 14px;
    font-weight: 700;
    letter-spacing: 0.16em;
}

.cta-panel {
    text-align: center;
}

.cta-panel h2 {
    font-size: clamp(2.2rem, 4vw, 4.4rem);
}

.cta-panel p {
    max-width: 760px;
    margin: 18px auto 0;
}

.cta-panel .hero-actions {
    justify-content: center;
}

@keyframes queenPulse {
    0%,
    100% {
        transform: scale(1) translateY(0);
    }

    50% {
        transform: scale(1.08) translateY(-2px);
    }
}

@media (max-width: 980px) {
    .hero {
        grid-template-columns: 1fr;
        gap: 28px;
        padding-top: 54px;
    }

    .hero-visual {
        min-height: auto;
    }

    .journey-grid,
    .feature-grid,
    .hero-facts {
        grid-template-columns: 1fr;
    }

    .solver-card,
    .timer-card {
        position: static;
    }

    .hero-visual {
        gap: 16px;
    }
}

@media (max-width: 760px) {
    .landing-nav {
        position: static;
        width: 100%;
        padding: 18px 16px;
        border-left-width: 0;
        border-right-width: 0;
        gap: 14px;
        align-items: flex-start;
        flex-direction: column;
    }

    .brand {
        width: 100%;
        justify-content: space-between;
        gap: 8px;
        font-size: 16px;
    }

    .brand-mark {
        display: none;
    }

    .landing-links {
        justify-content: flex-start;
        gap: 10px;
        width: 100%;
    }

    .landing-links a:not(.nav-cta),
    .lang-switch,
    .nav-cta {
        padding: 11px 14px;
    }

    main {
        width: min(100%, calc(100vw - 24px));
    }

    .hero h1,
    .info-band h2,
    .section-heading h2,
    .cta-panel h2 {
        line-height: 1.02;
    }

    .info-band-inner,
    .cta-panel,
    .feature-card,
    .journey-step {
        padding: 24px;
    }

    .floating-card {
        width: 100%;
    }
}