```css
/* =============================================
   每日大赛 mrds.fun · 设计系统
   风格：Neo-Brutalist Arena / 新粗野主义赛场
   背景：暖奶油色 + 亮色块 · 无暗色背景
   ============================================= */

:root {
  --ink: #1A1A2E;
  --cream: #FAF3E7;
  --cream-2: #F0E8DB;
  --blue: #E0EDF7;
  --coral: #FF3D5E;
  --teal: #00B8A9;
  --yellow: #FFC531;
  --white: #FFFFFF;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  overflow-x: hidden;
  background: var(--cream);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3 {
  text-wrap: balance;
}

::selection {
  background: var(--yellow);
  color: var(--ink);
}

:focus-visible {
  outline: 3px solid var(--coral);
  outline-offset: 2px;
}

::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
::-webkit-scrollbar-track {
  background: var(--cream);
  border-left: 2px solid var(--ink);
}
::-webkit-scrollbar-thumb {
  background: var(--ink);
  border: 2px solid var(--cream);
  border-radius: 0;
}

/* 噪点纸张质感 */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.025;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='250' height='250'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.6' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ============ 核心布局 ============ */

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 100px 0;
  position: relative;
}

.section:nth-child(even) {
  background: var(--blue);
}

/* ============ 固定导航 ============ */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(250, 243, 231, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 3px solid var(--ink);
  box-shadow: 0 4px 0 rgba(26, 26, 46, 0.08);
}

.site-header::before {
  content: '';
  position: absolute;
  left: 20px;
  bottom: -8px;
  width: 14px;
  height: 14px;
  background: var(--teal);
  border: 2.5px solid var(--ink);
  transform: rotate(45deg);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 900;
  font-size: 1.25rem;
  text-decoration: none;
  color: var(--ink);
  letter-spacing: -0.5px;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--yellow);
  border: 3px solid var(--ink);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.15rem;
  font-weight: 900;
  color: var(--ink);
  transform: rotate(-6deg);
  box-shadow: 3px 3px 0 var(--ink);
  transition: transform 0.25s ease;
}

.logo:hover .logo-icon {
  transform: rotate(0deg) scale(1.06);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.main-nav a {
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--ink);
  position: relative;
  padding: 4px 0;
  transition: color 0.2s;
}

.main-nav a::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 3px;
  background: var(--coral);
  transition: width 0.25s ease;
}

.main-nav a:hover::after {
  width: 100%;
}

.nav-cta {
  padding: 10px 22px;
  border: 3px solid var(--ink);
  border-radius: 0;
  background: var(--coral);
  color: #fff !important;
  font-weight: 800;
  box-shadow: 4px 4px 0 var(--ink);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  background-image: repeating-linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.08) 0,
    rgba(255, 255, 255, 0.08) 8px,
    transparent 8px,
    transparent 16px
  );
}

.nav-cta:hover {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0 var(--ink);
}

.nav-cta::after {
  display: none;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  width: 42px;
  height: 42px;
  border: 3px solid var(--ink);
  background: var(--white);
  cursor: pointer;
  box-shadow: 3px 3px 0 var(--ink);
  transition: transform 0.2s;
}

.menu-toggle:hover {
  transform: rotate(4deg);
}

.menu-toggle span {
  display: block;
  width: 20px;
  height: 3px;
  background: var(--ink);
  transition: transform 0.25s, opacity 0.2s;
}

.menu-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.menu-toggle.open span:nth-child(2) {
  opacity: 0;
}
.menu-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ============ 首页 Hero ============ */

.hero {
  min-height: 70vh;
  display: flex;
  align-items: center;
  padding: 160px 0 100px;
  position: relative;
  overflow: hidden;
  background-color: var(--cream);
  background-image:
    linear-gradient(rgba(26, 26, 46, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(26, 26, 46, 0.035) 1px, transparent 1px);
  background-size: 44px 44px;
}

.hero::before {
  content: '胜';
  position: absolute;
  right: 5%;
  bottom: -5%;
  font-size: 20rem;
  font-weight: 900;
  line-height: 1;
  color: rgba(26, 26, 46, 0.035);
  pointer-events: none;
  z-index: 0;
}

.hero .container {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 64px;
  align-items: center;
  width: 100%;
}

.hero-content {
  max-width: 720px;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 800;
  padding: 6px 16px;
  background: var(--yellow);
  border: 2.5px solid var(--ink);
  border-radius: 0;
  box-shadow: 3px 3px 0 var(--ink);
  margin-bottom: 20px;
  transform: rotate(-2deg);
  letter-spacing: 1.5px;
  text-transform: uppercase;
}

.hero h1 {
  font-size: 3.6rem;
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 20px;
  letter-spacing: -1px;
}

.hero h1 .text-accent {
  color: var(--coral);
}

.hero p {
  font-size: 1.15rem;
  opacity: 0.72;
  max-width: 560px;
  margin-bottom: 36px;
  line-height: 1.8;
}

.hero-buttons {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

.hero-image {
  position: relative;
  background: var(--white);
  border: 3px solid var(--ink);
  border-radius: 0;
  box-shadow: 12px 12px 0 var(--ink);
  padding: 14px;
  transform: rotate(2deg);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hero-image:hover {
  transform: rotate(0deg) translateY(-4px);
  box-shadow: 14px 14px 0 var(--teal);
}

.hero-image img {
  display: block;
  width: 100%;
  height: auto;
  border: 2px solid var(--ink);
  filter: grayscale(10%) contrast(1.02);
}

.hero-image::before {
  content: '🏆 每日开赛';
  position: absolute;
  top: 18px;
  right: 18px;
  background: var(--coral);
  color: #fff;
  border: 2.5px solid var(--ink);
  padding: 6px 14px;
  font-size: 0.75rem;
  font-weight: 800;
  z-index: 2;
  box-shadow: 3px 3px 0 var(--ink);
  transform: rotate(4deg);
}

.hero-image::after {
  content: '';
  position: absolute;
  top: -14px;
  left: 28px;
  width: 64px;
  height: 18px;
  background: rgba(255, 197, 49, 0.65);
  border: 2px solid rgba(26, 26, 46, 0.25);
  transform: rotate(-5deg);
}

/* ============ 按钮 ============ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 30px;
  border-radius: 0;
  border: 3px solid var(--ink);
  font-weight: 700;
  font-size: 0.95rem;
  line-height: 1.2;
  cursor: pointer;
  text-decoration: none;
  font-family: inherit;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.2s ease;
  box-shadow: 5px 5px 0 var(--ink);
}

.btn-primary {
  background: var(--coral);
  color: #fff !important;
}

.btn-primary:hover {
  background: #FF1F47;
  transform: translate(2px, 2px);
  box-shadow: 3px 3px 0 var(--ink);
}

.btn-outline {
  background: transparent;
  color: var(--ink);
}

.btn-outline:hover {
  background: var(--blue);
  transform: translate(2px, 2px);
  box-shadow: 3px 3px 0 var(--ink);
}

.btn:active {
  transform: translate(4px, 4px);
  box-shadow: 1px 1px 0 var(--ink);
}

/* ============ 标签 / 标题 ============ */

.section-label {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 2px;
  text-transform: uppercase;
  background: var(--yellow);
  border: 2.5px solid var(--ink);
  padding: 5px 14px;
  margin-bottom: 16px;
  transform: rotate(-2deg);
  box-shadow: 3px 3px 0 var(--ink);
}

.section-title {
  font-size: 2.4rem;
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 14px;
  display: inline-block;
  background: linear-gradient(
    to bottom,
    transparent 55%,
    rgba(255, 197, 49, 0.35) 55%
  );
  padding: 0 4px;
}

.section-desc {
  max-width: 600px;
  opacity: 0.7;
  margin-bottom: 48px;
  font-size: 1.05rem;
  line-height: 1.8;
}

/* ============ 卡片网格 ============ */

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 28px;
}

.category-card {
  background: var(--white);
  border: 3px solid var(--ink);
  border-radius: 0;
  padding: 30px 28px;
  box-shadow: 5px 5px 0 var(--ink);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  position: relative;
}

.category-card:hover {
  transform: translate(-4px, -4px);
  box-shadow: 10px 10px 0 var(--ink);
}

.category-card::after {
  content: '';
  position: absolute;
  top: 12px;
  right: 12px;
  width: 10px;
  height: 10px;
  border: 2px solid var(--ink);
  border-radius: 50%;
}

.category-card:nth-child(3n+1)::after {
  background: var(--coral);
}
.category-card:nth-child(3n+2)::after {
  background: var(--teal);
}
.category-card:nth-child(3n+3)::after {
  background: var(--yellow);
}

.card-icon {
  width: 52px;
  height: 52px;
  border: 3px solid var(--ink);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  font-size: 1.4rem;
  background: var(--blue);
  transform: rotate(-5deg);
  transition: transform 0.25s;
}

.category-card:hover .card-icon {
  transform: rotate(0deg) scale(1.05);
}

.category-card:nth-child(3n+1) .card-icon {
  background: rgba(255, 61, 94, 0.15);
}
.category-card:nth-child(3n+2) .card-icon {
  background: rgba(0, 184, 169, 0.15);
}
.category-card:nth-child(3n+3) .card-icon {
  background: rgba(255, 197, 49, 0.2);
}

.category-card h3 {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.category-card p {
  font-size: 0.9rem;
  opacity: 0.65;
  margin-bottom: 16px;
  line-height: 1.6;
}

.card-link {
  font-weight: 700;
  font-size: 0.85rem;
  text-decoration: none;
  color: var(--ink);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: color 0.2s;
}

.card-link::after {
  content: '→';
  transition: transform 0.2s;
}

.card-link:hover {
  color: var(--coral);
}

.card-link:hover::after {
  transform: translateX(5px);
}

/* ============ 特性块 ============ */

.feature-block {
  display: grid;
  grid-template-columns: 1fr 1