/* ===== OIStar 信奥训练营 · 深色科技主题 ===== */
:root {
  --bg: #070b14;
  --bg-soft: #0b1120;
  --card: #0e1628;
  --card-2: #0a1120;
  --border: #1c2a45;
  --border-hi: #2b3f66;
  --text: #e6edff;
  --muted: #8ea3c9;
  --primary: #38bdf8;
  --primary-dark: #0ea5e9;
  --accent: #818cf8;
  --accent2: #22d3ee;
  --glow: rgba(56, 189, 248, 0.35);
  --ac: #34d399;        --ac-bg: rgba(52, 211, 153, 0.13);
  --wa: #f87171;        --wa-bg: rgba(248, 113, 113, 0.13);
  --tle: #fbbf24;       --tle-bg: rgba(251, 191, 36, 0.13);
  --re: #c084fc;        --re-bg: rgba(192, 132, 252, 0.13);
  --ce: #60a5fa;        --ce-bg: rgba(96, 165, 250, 0.13);
  --pe: #2dd4bf;        --pe-bg: rgba(45, 212, 191, 0.13);
  --je: #94a3b8;        --je-bg: rgba(148, 163, 184, 0.13);
  --pending: #64748b;   --pending-bg: rgba(100, 116, 139, 0.15);
  --radius: 10px;
  --mono: "Cascadia Code", Consolas, "JetBrains Mono", monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }
::selection { background: rgba(56, 189, 248, 0.35); color: #fff; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background:
    radial-gradient(1100px 520px at 85% -10%, rgba(56, 189, 248, 0.09), transparent 60%),
    radial-gradient(900px 480px at -10% 25%, rgba(129, 140, 248, 0.08), transparent 55%),
    radial-gradient(700px 500px at 50% 110%, rgba(34, 211, 238, 0.05), transparent 60%),
    var(--bg);
  background-attachment: fixed;
  color: var(--text);
  font-size: 15px;
  line-height: 1.6;
  min-height: 100vh;
}
a { color: var(--primary); text-decoration: none; }
a:hover { color: #7dd3fc; text-shadow: 0 0 12px var(--glow); }
.container { max-width: 1100px; margin: 0 auto; padding: 0 16px; }

/* 滚动条 */
::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-track { background: var(--bg-soft); }
::-webkit-scrollbar-thumb { background: #233350; border-radius: 6px; }
::-webkit-scrollbar-thumb:hover { background: #2e4468; }

/* ===== 顶栏 ===== */
.topbar {
  background: rgba(9, 14, 26, 0.82);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 100;
}
.nav { display: flex; align-items: center; height: 58px; gap: 24px; }
.logo { display: flex; align-items: baseline; gap: 8px; font-size: 21px; font-weight: 800; letter-spacing: 1px; color: var(--text); font-family: var(--mono); }
.logo b {
  background: linear-gradient(90deg, #38bdf8, #818cf8 60%, #22d3ee);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  filter: drop-shadow(0 0 10px rgba(56, 189, 248, 0.45));
}
.logo small { font-size: 12px; color: var(--muted); font-weight: 500; letter-spacing: 2px; font-family: inherit; }
.nav-links { display: flex; align-items: center; gap: 4px; flex: 1; }
.nav-links a { padding: 6px 12px; border-radius: 8px; color: #b6c6e8; font-weight: 500; }
.nav-links a:hover { background: rgba(56, 189, 248, 0.1); color: #7dd3fc; text-shadow: none; }
.nav-links a.active {
  background: rgba(56, 189, 248, 0.12);
  color: #7dd3fc;
  box-shadow: inset 0 -2px 0 var(--primary), 0 0 14px rgba(56, 189, 248, 0.15);
}
.nav-right { display: flex; align-items: center; gap: 10px; margin-left: auto; }

.btn {
  display: inline-block; padding: 7px 16px; border-radius: 8px; border: 1px solid var(--border-hi);
  background: linear-gradient(180deg, #131d33, #0e1628);
  color: var(--text); font-size: 14px; font-weight: 600; cursor: pointer;
  transition: all .18s; text-align: center;
}
.btn:hover { border-color: var(--primary); color: #7dd3fc; box-shadow: 0 0 14px rgba(56, 189, 248, 0.25); }
.btn-primary {
  background: linear-gradient(135deg, #0ea5e9, #6366f1 80%);
  border-color: rgba(56, 189, 248, 0.6);
  color: #fff;
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.3);
}
.btn-primary:hover { color: #fff; filter: brightness(1.15); box-shadow: 0 0 22px rgba(56, 189, 248, 0.5); }
.btn-danger { background: #1a1024; border-color: rgba(248, 113, 113, 0.45); color: var(--wa); }
.btn-danger:hover { background: rgba(248, 113, 113, 0.12); border-color: var(--wa); color: #fca5a5; }
.btn-sm { padding: 4px 10px; font-size: 13px; }
.burger { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--text); padding: 4px 8px; }

/* 移动端菜单 */
@media (max-width: 860px) {
  .burger { display: block; }
  .nav { flex-wrap: wrap; height: auto; padding: 10px 16px; gap: 10px; }
  .nav-links {
    display: none; width: 100%; flex-direction: column; align-items: stretch;
    background: rgba(9, 14, 26, 0.97); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 8px; margin-bottom: 6px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 10px 12px; }
  .nav-right { margin-left: auto; }
}

/* ===== 卡片 / 通用 ===== */
.card {
  background: linear-gradient(180deg, rgba(22, 33, 56, 0.55), rgba(11, 17, 32, 0.92));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.35), inset 0 1px 0 rgba(148, 187, 255, 0.06);
  padding: 20px; margin-bottom: 16px;
  transition: border-color .2s, box-shadow .2s;
}
.card:hover { border-color: var(--border-hi); }
.card h2 { font-size: 18px; margin-bottom: 12px; color: #dbe7ff; }
.muted { color: var(--muted); }
.small { font-size: 13px; }
.mt8 { margin-top: 8px; } .mt16 { margin-top: 16px; } .mt24 { margin-top: 24px; }
.flex { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.spread { justify-content: space-between; }
.center { text-align: center; }

/* 难度徽章 */
.diff { display: inline-block; padding: 1px 10px; border-radius: 999px; font-size: 12px; font-weight: 700; font-family: var(--mono); }
.diff-1 { background: rgba(52, 211, 153, 0.16); color: #34d399; border: 1px solid rgba(52, 211, 153, 0.4); box-shadow: 0 0 8px rgba(52, 211, 153, 0.15); }
.diff-2 { background: rgba(45, 212, 191, 0.16); color: #2dd4bf; border: 1px solid rgba(45, 212, 191, 0.4); }
.diff-3 { background: rgba(96, 165, 250, 0.16); color: #60a5fa; border: 1px solid rgba(96, 165, 250, 0.4); }
.diff-4 { background: rgba(251, 191, 36, 0.15); color: #fbbf24; border: 1px solid rgba(251, 191, 36, 0.4); }
.diff-5 { background: rgba(248, 113, 113, 0.16); color: #f87171; border: 1px solid rgba(248, 113, 113, 0.45); box-shadow: 0 0 8px rgba(248, 113, 113, 0.15); }

/* 评测结果徽章 */
.verdict { display: inline-block; padding: 1px 10px; border-radius: 6px; font-size: 12px; font-weight: 700; font-family: var(--mono); }
.v-AC { background: var(--ac-bg); color: var(--ac); border: 1px solid rgba(52, 211, 153, 0.35); }
.v-WA { background: var(--wa-bg); color: var(--wa); border: 1px solid rgba(248, 113, 113, 0.35); }
.v-TLE { background: var(--tle-bg); color: var(--tle); border: 1px solid rgba(251, 191, 36, 0.35); }
.v-RE { background: var(--re-bg); color: var(--re); border: 1px solid rgba(192, 132, 252, 0.35); }
.v-CE { background: var(--ce-bg); color: var(--ce); border: 1px solid rgba(96, 165, 250, 0.35); }
.v-PE { background: var(--pe-bg); color: var(--pe); border: 1px solid rgba(45, 212, 191, 0.35); }
.v-JE { background: var(--je-bg); color: var(--je); border: 1px solid rgba(148, 163, 184, 0.35); }
.v-Pending, .v-Judging { background: var(--pending-bg); color: #93a5c4; border: 1px solid rgba(100, 116, 139, 0.3); }

/* 标签 */
.tag {
  display: inline-block; padding: 1px 10px; border-radius: 6px;
  background: rgba(56, 189, 248, 0.1); color: #7dd3fc;
  border: 1px solid rgba(56, 189, 248, 0.25);
  font-size: 12px; margin: 2px;
}
.tag:hover { border-color: var(--primary); box-shadow: 0 0 10px rgba(56, 189, 248, 0.2); }

/* 表格 */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { padding: 10px 12px; text-align: left; border-bottom: 1px solid rgba(35, 50, 80, 0.7); white-space: nowrap; }
th { color: var(--muted); font-weight: 600; font-size: 13px; background: rgba(9, 14, 26, 0.7); letter-spacing: 0.5px; }
tr:hover td { background: rgba(56, 189, 248, 0.045); }

/* 表单 */
input[type=text], input[type=password], input[type=number], input[type=datetime-local], select, textarea {
  width: 100%; padding: 9px 12px; border: 1px solid var(--border-hi); border-radius: 8px;
  font-size: 14px; font-family: inherit; background: #0a1120; color: var(--text);
}
input:focus, select:focus, textarea:focus {
  outline: none; border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15), 0 0 12px rgba(56, 189, 248, 0.15);
}
label { display: block; font-size: 13px; font-weight: 600; color: var(--muted); margin: 12px 0 4px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
@media (max-width: 640px) { .form-row { grid-template-columns: 1fr; } }

/* 分页 */
.pagination { display: flex; gap: 6px; justify-content: center; align-items: center; margin-top: 16px; flex-wrap: wrap; }
.pagination button {
  min-width: 34px; padding: 6px 10px; border: 1px solid var(--border-hi); background: #0e1628;
  border-radius: 8px; cursor: pointer; font-size: 13px; color: var(--text);
}
.pagination button:hover { border-color: var(--primary); color: #7dd3fc; }
.pagination button.active { background: linear-gradient(135deg, #0ea5e9, #6366f1); border-color: transparent; color: #fff; box-shadow: 0 0 12px rgba(56, 189, 248, 0.35); }
.pagination button:disabled { opacity: .35; cursor: not-allowed; }

/* 题面 */
.problem-statement h3 { font-size: 15px; margin: 18px 0 8px; color: #cfe0ff; border-left: 3px solid var(--primary); padding-left: 8px; }
.problem-statement p { margin: 8px 0; }
.problem-statement ul, .problem-statement ol { margin: 8px 0 8px 24px; }
.problem-statement pre {
  background: #060a14; color: #c8dcff; border: 1px solid var(--border);
  padding: 12px 14px; border-radius: 8px;
  overflow-x: auto; font-size: 13px; line-height: 1.7; font-family: var(--mono);
}
.problem-statement code { background: rgba(56, 189, 248, 0.12); color: #7dd3fc; padding: 1px 6px; border-radius: 4px; font-size: 13px; font-family: var(--mono); }
.problem-statement pre code { background: none; padding: 0; color: inherit; }
.problem-statement img { border-radius: 6px; }
.sample { margin: 10px 0; }
.sample-title { font-size: 13px; font-weight: 700; color: var(--muted); margin-bottom: 4px; font-family: var(--mono); letter-spacing: 0.5px; }

/* 编辑器 */
.editor-wrap { border: 1px solid var(--border); border-radius: 8px; overflow: hidden; background: #060a14; box-shadow: 0 0 20px rgba(0, 0, 0, 0.4); }
.editor-header { display: flex; align-items: center; gap: 8px; background: #0d1526; padding: 8px 12px; border-bottom: 1px solid var(--border); }
.editor-header select { width: auto; background: #16213a; color: #c8dcff; border-color: #2b3f66; }
.editor-body { display: flex; position: relative; }
.editor-gutter {
  width: 44px; background: #060a14; color: #2e4468; text-align: right; padding: 12px 8px 12px 0;
  font-family: var(--mono); font-size: 13px; line-height: 1.6; user-select: none;
  overflow: hidden; flex-shrink: 0; height: 420px;
}
.editor-body textarea {
  flex: 1; background: #060a14; color: #d5e5ff; border: none; resize: none; outline: none;
  font-family: var(--mono); font-size: 13px; line-height: 1.6;
  padding: 12px; min-height: 420px; tab-size: 4; white-space: pre; overflow: auto;
}

/* 提示 */
.toast {
  position: fixed; top: 70px; left: 50%; transform: translateX(-50%);
  background: rgba(13, 21, 38, 0.95); border: 1px solid var(--border-hi);
  color: #fff; padding: 10px 20px; border-radius: 8px; font-size: 14px;
  z-index: 999; box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5), 0 0 18px rgba(56, 189, 248, 0.15);
  opacity: 0; transition: opacity .25s; pointer-events: none;
}
.toast.show { opacity: 1; }
.toast.error { border-color: rgba(248, 113, 113, 0.6); box-shadow: 0 8px 30px rgba(0, 0, 0, 0.5), 0 0 18px rgba(248, 113, 113, 0.2); }

/* ===== 首页 hero（科技网格 + 光效） ===== */
.hero {
  position: relative;
  background:
    linear-gradient(135deg, rgba(14, 165, 233, 0.16), rgba(99, 102, 241, 0.14) 60%, rgba(34, 211, 238, 0.1)),
    var(--card);
  border: 1px solid rgba(56, 189, 248, 0.3);
  border-radius: 14px;
  padding: 40px 34px; margin: 20px 0;
  overflow: hidden;
  box-shadow: 0 0 40px rgba(56, 189, 248, 0.12), inset 0 0 60px rgba(56, 189, 248, 0.05);
}
.hero::before { /* 网格纹理 */
  content: ""; position: absolute; inset: 0; pointer-events: none; z-index: 1;
  background-image:
    linear-gradient(rgba(56, 189, 248, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(56, 189, 248, 0.06) 1px, transparent 1px);
  background-size: 30px 30px;
  mask-image: radial-gradient(ellipse at 30% 20%, rgba(0, 0, 0, 0.9), transparent 70%);
}
.hero::after { /* 顶部扫描光带 */
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 1px; z-index: 2;
  background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.8), transparent);
  animation: scan 5s ease-in-out infinite;
}
@keyframes scan { 0%, 100% { opacity: .3; } 50% { opacity: 1; } }
.hero h1 {
  font-size: 30px; margin-bottom: 12px; position: relative; z-index: 1;
  background: linear-gradient(90deg, #e6f2ff, #7dd3fc 45%, #a5b4fc);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  filter: drop-shadow(0 0 18px rgba(56, 189, 248, 0.35));
  letter-spacing: 1px;
}
.hero p { opacity: .9; max-width: 640px; position: relative; z-index: 1; color: #b9c9ec; }
.hero .stats { display: flex; gap: 38px; margin-top: 26px; position: relative; z-index: 1; flex-wrap: wrap; }
.hero .stats div b {
  font-size: 27px; display: block; font-family: var(--mono); color: #7dd3fc;
  text-shadow: 0 0 14px rgba(56, 189, 248, 0.5);
}
.hero .stats div span { font-size: 13px; opacity: .8; color: var(--muted); letter-spacing: 1px; }
.hero .mt24 { position: relative; z-index: 1; }
.hero .btn-plain { border-color: rgba(125, 211, 252, 0.6); color: #7dd3fc; background: transparent; }
.hero .btn-plain:hover { box-shadow: 0 0 14px rgba(56, 189, 248, 0.3); color: #bae6fd; }

/* 漂浮代码装饰 */
.code-chips { position: absolute; inset: 0; pointer-events: none; z-index: 0; overflow: hidden; }
.code-chips span {
  position: absolute; font-family: var(--mono); font-size: 13px; color: rgba(56, 189, 248, 0.22);
  white-space: nowrap; animation: floatY 7s ease-in-out infinite;
}
@keyframes floatY { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-8px); } }

/* 侧栏布局 */
.grid2 { display: grid; grid-template-columns: 1fr 360px; gap: 16px; align-items: start; }
@media (max-width: 960px) { .grid2 { grid-template-columns: 1fr; } }

/* 登录卡片 */
.auth-card { max-width: 420px; margin: 60px auto; border-color: var(--border-hi); box-shadow: 0 0 40px rgba(56, 189, 248, 0.08); }

/* 后台 tab */
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 16px; }
.tabs button {
  padding: 8px 18px; border: 1px solid var(--border-hi); background: #0e1628; border-radius: 8px;
  font-size: 14px; font-weight: 600; cursor: pointer; color: var(--muted);
}
.tabs button:hover { color: #7dd3fc; border-color: var(--primary); }
.tabs button.active { background: linear-gradient(135deg, #0ea5e9, #6366f1); border-color: transparent; color: #fff; box-shadow: 0 0 14px rgba(56, 189, 248, 0.3); }

/* 代码展示 */
.code-block {
  background: #060a14; color: #c8dcff; border: 1px solid var(--border);
  padding: 14px; border-radius: 8px; overflow-x: auto;
  font-family: var(--mono); font-size: 13px; line-height: 1.7; max-height: 420px; overflow-y: auto;
}

.empty { text-align: center; color: var(--muted); padding: 40px 0; }
.hidden { display: none !important; }
.nowrap { white-space: nowrap; }
blockquote { border-left: 3px solid var(--primary); background: rgba(56, 189, 248, 0.06); padding: 8px 14px; border-radius: 0 8px 8px 0; margin: 8px 0; }
hr { border: none; border-top: 1px solid var(--border); margin: 14px 0; }