/* Python 课程教学站样式 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", sans-serif;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    color: #e8e8f0;
    min-height: 100vh;
    line-height: 1.7;
}
a { color: inherit; text-decoration: none; }

/* 顶栏 */
.topbar {
    position: sticky; top: 0; z-index: 50;
    display: flex; align-items: center; justify-content: space-between;
    padding: 14px 28px;
    background: rgba(15, 22, 45, 0.85);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255,255,255,0.08);
}
.brand { font-size: 20px; font-weight: 700;
    background: linear-gradient(90deg, #667eea, #43e97b);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.nav-links a { margin-left: 18px; font-size: 15px; opacity: 0.85; transition: opacity .2s; }
.nav-links a:hover { opacity: 1; color: #43e97b; }

.container { max-width: 1200px; margin: 0 auto; padding: 32px 20px 60px; }

/* 首页 hero */
.hero { text-align: center; padding: 48px 20px 40px; }
.hero h1 {
    font-size: 40px;
    background: linear-gradient(90deg, #667eea, #f093fb, #4facfe, #43e97b);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    margin-bottom: 16px;
}
.hero p { font-size: 17px; opacity: 0.85; max-width: 720px; margin: 0 auto; }
.stats { display: flex; justify-content: center; gap: 48px; margin-top: 32px; flex-wrap: wrap; }
.stat { text-align: center; }
.stat .num { display: block; font-size: 34px; font-weight: 700; color: #4facfe; }
.stat .lbl { font-size: 13px; opacity: 0.7; }

/* 区块 */
.section { margin-bottom: 48px; }
.section-title {
    font-size: 22px; margin-bottom: 20px; padding-left: 12px;
    border-left: 4px solid #43e97b; color: #fff;
}
.muted { opacity: 0.65; font-size: 14px; }
.center { text-align: center; }

/* 级别卡片 */
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px,1fr)); gap: 22px; }
.card-grid.sm { grid-template-columns: repeat(auto-fill, minmax(180px,1fr)); }
.level-card {
    background: rgba(255,255,255,0.06); border: 1px solid rgba(255,255,255,0.1);
    border-radius: 16px; padding: 26px; transition: transform .25s, box-shadow .25s;
}
.level-card:hover { transform: translateY(-5px); box-shadow: 0 12px 40px rgba(0,0,0,0.35); }
.level-badge {
    width: 52px; height: 52px; border-radius: 14px; display: flex;
    align-items: center; justify-content: center; font-weight: 700; font-size: 16px;
    margin-bottom: 14px; color: #fff;
}
.color-0 .level-badge { background: linear-gradient(135deg,#667eea,#764ba2); }
.color-1 .level-badge { background: linear-gradient(135deg,#43e97b,#38f9d7); color:#0f3460; }
.color-2 .level-badge { background: linear-gradient(135deg,#fa709a,#fee140); color:#0f3460; }
.color-3 .level-badge { background: linear-gradient(135deg,#4facfe,#00f2fe); color:#0f3460; }
.level-card h3 { font-size: 19px; margin-bottom: 6px; }
.level-card p { font-size: 13px; opacity: 0.7; }
.level-card .go { display: inline-block; margin-top: 14px; color: #43e97b; font-size: 14px; }

/* 课程卡片 */
.lesson-card {
    background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1);
    border-radius: 12px; padding: 16px; display: flex; flex-direction: column; gap: 8px;
    transition: transform .2s, background .2s;
}
.lesson-card:hover { transform: translateY(-4px); background: rgba(255,255,255,0.1); }
.lesson-card.alt { border-color: rgba(250,112,154,0.3); }
.lesson-card .num { font-size: 13px; color: #4facfe; font-weight: 700; }
.lesson-card .title { font-size: 14px; opacity: 0.9; flex: 1; }
.lesson-card .tag { font-size: 11px; opacity: 0.6; align-self: flex-start; }

/* 文档列表 */
.doc-list { display: flex; flex-direction: column; gap: 10px; }
.doc-item {
    display: flex; align-items: center; gap: 12px;
    background: rgba(255,255,255,0.04); border: 1px solid rgba(255,255,255,0.08);
    border-radius: 10px; padding: 14px 18px; transition: background .2s, transform .2s;
}
.doc-item:hover { background: rgba(255,255,255,0.09); transform: translateX(4px); }
.doc-item .doc-num { font-size: 18px; }
.doc-item .doc-title { flex: 1; font-size: 15px; }
.doc-item .go { color: #43e97b; font-size: 14px; }

/* 课程体系行 */
.sys-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px,1fr)); gap: 22px; }
.sys-card {
    background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1);
    border-radius: 16px; padding: 26px; transition: transform .25s, box-shadow .25s;
}
.sys-card:hover { transform: translateY(-4px); box-shadow: 0 10px 36px rgba(0,0,0,0.3); }
.sys-card.alt { background: rgba(79,172,254,0.08); }
.sys-card h3 { font-size: 18px; margin-bottom: 8px; color: #4facfe; }
.sys-card p { font-size: 14px; opacity: 0.75; }

/* 文档阅读 */
.doc-view .doc-head {
    display: flex; align-items: center; gap: 16px; margin-bottom: 22px; flex-wrap: wrap;
}
.doc-h1 { font-size: 26px; flex: 1; }
.back, .raw { font-size: 14px; opacity: 0.85; }
.back:hover, .raw:hover { color: #43e97b; opacity: 1; }
.markdown-body {
    background: rgba(255,255,255,0.97); color: #24292e; border-radius: 14px;
    padding: 36px 44px; line-height: 1.8; font-size: 15px;
}
.markdown-body h1, .markdown-body h2, .markdown-body h3 { margin: 22px 0 12px; line-height: 1.4; }
.markdown-body h1 { font-size: 26px; border-bottom: 2px solid #e1e4e8; padding-bottom: 8px; }
.markdown-body h2 { font-size: 21px; border-bottom: 1px solid #e1e4e8; padding-bottom: 6px; margin-top: 30px; }
.markdown-body h3 { font-size: 17px; }
.markdown-body p { margin: 10px 0; }
.markdown-body ul, .markdown-body ol { margin: 10px 0 10px 28px; }
.markdown-body li { margin: 4px 0; }
.markdown-body code {
    background: #f6f8fa; padding: 2px 6px; border-radius: 4px; font-size: 13px;
    font-family: Consolas, "Courier New", monospace; color: #d6336c;
}
.markdown-body pre {
    background: #0d1117; color: #e6edf3; padding: 16px; border-radius: 8px;
    overflow-x: auto; margin: 14px 0;
}
.markdown-body pre code { background: none; color: inherit; padding: 0; }
.markdown-body table { border-collapse: collapse; margin: 14px 0; width: 100%; }
.markdown-body th, .markdown-body td { border: 1px solid #d0d7de; padding: 8px 12px; }
.markdown-body th { background: #f6f8fa; }
.markdown-body blockquote { border-left: 4px solid #4facfe; padding-left: 14px; color: #57606a; margin: 12px 0; }
.markdown-body a { color: #0969da; }
.markdown-body a:hover { text-decoration: underline; }

/* 课件 iframe */
.cw-wrap { display: flex; flex-direction: column; height: calc(100vh - 120px); }
.cw-bar {
    display: flex; align-items: center; gap: 16px; padding: 12px 16px;
    background: rgba(15,22,45,0.85); border-radius: 10px 10px 0 0;
    border: 1px solid rgba(255,255,255,0.08); border-bottom: none;
}
.cw-bar .cw-title { flex: 1; font-size: 15px; font-weight: 600; }
.cw-frame { flex: 1; width: 100%; border: 1px solid rgba(255,255,255,0.08);
    border-top: none; border-radius: 0 0 10px 10px; background: #fff; }

/* 页脚 */
.footer { text-align: center; padding: 24px; opacity: 0.6; font-size: 13px; }

.btn {
    display: inline-block; padding: 10px 22px; border-radius: 8px;
    background: linear-gradient(135deg,#667eea,#43e97b); color: #0f3460; font-weight: 600;
}
.level-h1 { font-size: 28px; margin-bottom: 8px; color: #43e97b; }

@media (max-width: 640px) {
    .hero h1 { font-size: 28px; }
    .nav-links a { margin-left: 10px; font-size: 13px; }
    .markdown-body { padding: 20px 16px; }
}

/* ===== 认证 / 个人中心 / 后台管理 ===== */
.nav-auth { display: flex; align-items: center; gap: 12px; }
.nav-auth a, .nav-auth button {
    font-size: 14px; opacity: 0.85; background: none; border: none;
    color: #e8e8f0; cursor: pointer; padding: 0; transition: opacity .2s;
}
.nav-auth a:hover, .nav-auth button:hover { opacity: 1; color: #43e97b; }
.nav-auth .login-btn {
    padding: 7px 18px; border-radius: 999px; color: #fff;
    background: linear-gradient(135deg,#667eea,#764ba2); font-weight: 600;
}
.nav-auth .login-btn:hover { color: #fff; opacity: .88; }
.uname-chip {
    display: inline-flex; align-items: center; gap: 8px; cursor: default;
    color: rgba(255,255,255,0.9); font-size: 14px;
}
.avatar-sm {
    width: 30px; height: 30px; border-radius: 50%; display: inline-flex;
    align-items: center; justify-content: center; font-size: 13px; font-weight: 700;
    background: linear-gradient(135deg,#667eea,#764ba2); color: #fff;
}

.flash { max-width: 1200px; margin: 0 auto 14px; padding: 11px 16px; border-radius: 8px; font-size: 14px; }
.flash-ok   { background: rgba(67,233,123,0.12);  border: 1px solid rgba(67,233,123,0.4);  color: #7bf2ab; }
.flash-error{ background: rgba(245,87,108,0.15); border: 1px solid rgba(245,87,108,0.45); color: #ff8a9b; }

/* 个人中心 */
.page-head { text-align: center; margin-bottom: 30px; }
.page-head h1 { font-size: 28px; color: #fff; margin-bottom: 6px; }
.page-head p { font-size: 14px; opacity: 0.65; }
.profile-grid { display: grid; grid-template-columns: 340px 1fr; gap: 22px; max-width: 980px; margin: 0 auto; }
.p-card {
    background: rgba(255,255,255,0.06); border: 1px solid rgba(255,255,255,0.1);
    border-radius: 16px; padding: 26px;
}
.p-card-hero { display: flex; flex-direction: column; align-items: center; text-align: center; gap: 14px;
    background: linear-gradient(160deg, rgba(102,126,234,0.22), rgba(240,147,251,0.1)); }
.avatar {
    width: 86px; height: 86px; border-radius: 50%; display: flex;
    align-items: center; justify-content: center; font-size: 34px; font-weight: 700; color: #fff;
    background: linear-gradient(135deg,#667eea,#f093fb);
}
.p-title h2 { font-size: 21px; color: #fff; }
.p-title p { font-size: 13px; opacity: 0.7; margin-top: 2px; }
.role-tag { font-size: 11px; padding: 3px 10px; border-radius: 999px; margin-left: 8px;
    background: rgba(67,233,123,0.15); border: 1px solid rgba(67,233,123,0.4); color: #7bf2ab; vertical-align: middle; }
.role-tag.role-admin { background: rgba(240,147,251,0.15); border-color: rgba(240,147,251,0.45); color: #f2a6fb; }
.status-dot { font-size: 12px; padding: 4px 14px; border-radius: 999px; }
.status-dot.on { background: rgba(67,233,123,0.12); color: #7bf2ab; }
.status-dot.off { background: rgba(245,87,108,0.14); color: #ff8a9b; }
.info-table { width: 100%; border-collapse: collapse; }
.info-table th, .info-table td { padding: 12px 10px; text-align: left; font-size: 14px;
    border-bottom: 1px dashed rgba(255,255,255,0.12); }
.info-table tr:last-child th, .info-table tr:last-child td { border-bottom: none; }
.info-table th { color: rgba(255,255,255,0.55); font-weight: normal; width: 110px; }
.notice-bar {
    max-width: 980px; margin: 24px auto 0; padding: 14px 20px; border-radius: 12px;
    background: rgba(79,172,254,0.08); border: 1px solid rgba(79,172,254,0.25);
    font-size: 13.5px; line-height: 1.9;
}
.notice-bar a { color: #4facfe; }
@media (max-width: 800px) { .profile-grid { grid-template-columns: 1fr; } }

/* 管理后台 */
.stat-row { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 20px; }
.stat-chip { padding: 8px 18px; border-radius: 999px; font-size: 13.5px;
    background: rgba(255,255,255,0.07); border: 1px solid rgba(255,255,255,0.12); }
.stat-chip b { color: #43e97b; margin-left: 4px; }
.panel {
    background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1);
    border-radius: 14px; padding: 24px; margin-bottom: 22px;
}
.panel-title { font-size: 17px; color: #fff; margin-bottom: 16px; }
.grid-form { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 14px; align-items: end; }
.grid-form label { display: flex; flex-direction: column; gap: 6px; font-size: 13px; color: rgba(255,255,255,0.7); }
.grid-form input {
    padding: 10px 12px; border-radius: 8px; outline: none; font-size: 14px; color: #fff;
    border: 1px solid rgba(255,255,255,0.16); background: rgba(255,255,255,0.07);
}
.grid-form input:focus { border-color: #667eea; box-shadow: 0 0 0 3px rgba(102,126,234,0.22); }
.btn-primary { justify-self: start; border: none; cursor: pointer;
    background: linear-gradient(135deg,#667eea,#764ba2); color: #fff; }
.table-wrap { overflow-x: auto; }
.users-table { width: 100%; border-collapse: collapse; min-width: 860px; }
.users-table th, .users-table td { padding: 10px 12px; font-size: 13.5px; text-align: left;
    border-bottom: 1px solid rgba(255,255,255,0.08); }
.users-table th { color: rgba(255,255,255,0.5); font-weight: normal; white-space: nowrap; }
.users-table tr.muted { opacity: 0.45; }
.users-table code { color: #4facfe; font-family: Consolas, monospace; }
.tag { font-size: 11px; padding: 2px 10px; border-radius: 999px;
    background: rgba(67,233,123,0.13); border: 1px solid rgba(67,233,123,0.35); color: #7bf2ab; }
.tag-admin { background: rgba(240,147,251,0.13); border-color: rgba(240,147,251,0.4); color: #f2a6fb; }
.dot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; margin-right: 7px; }
.dot.on { background: #43e97b; box-shadow: 0 0 6px rgba(67,233,123,0.8); }
.dot.off { background: #f5576c; }
.small { font-size: 12px !important; opacity: 0.75; }
.ops { display: flex; gap: 14px; align-items: center; flex-wrap: wrap; }
.inline-ops { display: inline-flex; gap: 6px; align-items: center; }
.pw-input { width: 130px; padding: 6px 10px; border-radius: 6px; font-size: 12.5px;
    border: 1px solid rgba(255,255,255,0.16); background: rgba(255,255,255,0.07); color: #fff; outline: none; }
.btn-sm { padding: 5px 12px; border-radius: 6px; font-size: 12.5px; cursor: pointer;
    border: 1px solid rgba(255,255,255,0.2); background: rgba(255,255,255,0.08); color: #fff; }
.btn-warn { background: rgba(245,87,108,0.18); border-color: rgba(245,87,108,0.4); }
.btn-ok { background: rgba(67,233,123,0.15); border-color: rgba(67,233,123,0.4); color: #7bf2ab; }
.btn-danger { background: rgba(245,87,108,0.2); border-color: rgba(245,87,108,0.5); }