:root {
    --bg-gradient: linear-gradient(135deg, #1f1c2c, #928dab);
    --accent: #f9a8d4;
    --accent-strong: #f472b6;
    --text-primary: #f5f5f5;
    --text-secondary: rgba(245, 245, 245, 0.8);
    --card-bg: rgba(31, 28, 44, 0.85);
    --border-glow: rgba(249, 168, 212, 0.4);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Zen Kaku Gothic New", "Microsoft YaHei", sans-serif;
    background: var(--bg-gradient);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 2.5rem;
    background: rgba(15, 13, 26, 0.65);
    backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 10;
}

.top-nav .brand {
    font-family: "Press Start 2P", monospace;
    letter-spacing: 2px;
    color: var(--accent);
}

.top-nav nav a {
    margin-left: 1.5rem;
    text-decoration: none;
    color: var(--text-secondary);
    transition: color 0.2s ease;
}

.top-nav nav a.active {
    color: var(--text-primary);
}

.top-nav nav a.cta {
    padding: 0.4rem 1.1rem;
    border-radius: 2rem;
    border: 1px solid var(--border-glow);
    color: var(--accent);
}

.top-nav nav a.cta.active {
    background: rgba(249, 168, 212, 0.2);
    color: var(--accent);
}

.top-nav nav a:hover {
    color: var(--text-primary);
}

main {
    flex: 1;
    width: min(1080px, 96%);
    margin: 0 auto;
    padding: 3rem 0 4rem;
}

.footer {
    text-align: center;
    padding: 1.5rem 0;
    color: var(--text-secondary);
    background: rgba(15, 13, 26, 0.65);
    backdrop-filter: blur(12px);
}

.hero {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 3rem;
    align-items: center;
    margin-bottom: 4rem;
}

.hero-content h1 {
    font-size: clamp(2.5rem, 5vw, 3.4rem);
    margin-bottom: 1rem;
}

.hero-content p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.85rem 1.8rem;
    border-radius: 2rem;
    background: var(--accent);
    color: #1f1c2c;
    text-decoration: none;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn.secondary {
    background: transparent;
    color: var(--accent);
    border: 1px solid var(--border-glow);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
}

.hero-illustration {
    position: relative;
    min-height: 280px;
}

.floating-orb {
    position: absolute;
    width: 160px;
    height: 160px;
    border-radius: 50%;
    background: radial-gradient(circle at 30% 30%, rgba(249, 168, 212, 0.9), transparent 70%);
    animation: float 6s ease-in-out infinite;
}

.orb-2 {
    top: 30%;
    left: 40%;
    width: 120px;
    height: 120px;
    animation-delay: 1.2s;
}

.orb-3 {
    bottom: 10%;
    right: 10%;
    width: 140px;
    height: 140px;
    animation-delay: 2.4s;
}

.cat-silhouette {
    position: absolute;
    bottom: 0;
    right: 0;
    font-size: 2.4rem;
    color: rgba(255, 255, 255, 0.9);
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-18px);
    }
}

.info-panels {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.panel {
    padding: 1.8rem;
    background: var(--card-bg);
    border-radius: 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
}

.panel h2 {
    margin-top: 0;
    margin-bottom: 1rem;
}

.panel ul,
.panel ol {
    color: var(--text-secondary);
    line-height: 1.8;
    padding-left: 1.2rem;
}

.page-header {
    margin-bottom: 2.5rem;
}

.page-header h1 {
    font-size: 2.2rem;
    margin-bottom: 0.75rem;
}

.page-header p {
    color: var(--text-secondary);
    margin: 0;
}

.challenge-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.5rem;
}

.challenge-card {
    background: var(--card-bg);
    padding: 1.6rem;
    border-radius: 1.3rem;
    border: 1px solid rgba(255, 255, 255, 0.06);
    position: relative;
    overflow: hidden;
}

.challenge-card::after {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at top right, rgba(249, 168, 212, 0.18), transparent 55%);
    pointer-events: none;
}

.challenge-card .meta {
    color: var(--accent);
    font-weight: 600;
    margin-bottom: 0.8rem;
}

.challenge-card p {
    color: var(--text-secondary);
    margin: 0;
}

.submission-form form {
    display: grid;
    gap: 1rem;
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.28);
}

.submission-form label {
    font-weight: 600;
}

.submission-form input,
.submission-form textarea {
    padding: 0.75rem 1rem;
    border-radius: 1rem;
    border: 1px solid transparent;
    background: rgba(255, 255, 255, 0.12);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
}

.submission-form textarea {
    resize: vertical;
}

.submission-form input:focus,
.submission-form textarea:focus {
    outline: none;
    border-color: var(--accent-strong);
    box-shadow: 0 0 0 3px rgba(244, 114, 182, 0.28);
}

.form-hint {
    margin-top: 1rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.flash-wrapper {
    margin-bottom: 1.5rem;
}

.flash {
    padding: 1rem 1.2rem;
    border-radius: 1rem;
    margin-bottom: 1rem;
    font-weight: 600;
    color: #1f1c2c;
}

.flash-success {
    background: #bef264;
}

.flash-warning {
    background: #facc15;
}

.flash-error {
    background: #f87171;
}

@media (max-width: 640px) {
    .top-nav {
        padding: 1rem 1.5rem;
    }

    .top-nav nav a {
        margin-left: 1rem;
    }

    main {
        width: 92%;
        padding-bottom: 3rem;
    }
}