/* 萤窗星途智慧教育平台 - 通用样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', Arial, sans-serif;
    /* 星点直接叠入背景，确保所有页面都能明显看到 */
    background-image:
        radial-gradient(circle, rgba(255, 255, 255, 0.95) 1.8px, rgba(255, 255, 255, 0) 2.8px),
        radial-gradient(circle, rgba(99, 102, 241, 0.75) 1.8px, rgba(99, 102, 241, 0) 3.0px),
        linear-gradient(160deg, #f0f4ff 0%, #e8eeff 50%, #f5f3ff 100%);
    background-repeat: repeat, repeat, no-repeat;
    background-size: 40px 40px, 70px 70px, auto;
    background-position: 8px 16px, 30px 10px, 0 0;
    color: #1e293b;
    line-height: 1.6;
    position: relative;
    overflow-x: hidden;
    z-index: 0; /* 创建层叠上下文，便于背景星光叠层正确显示 */
    animation: starDrift 7s ease-in-out infinite;
}

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

button {
    border: none;
    outline: none;
    cursor: pointer;
    font-family: inherit;
}

input, select, textarea {
    outline: none;
    font-family: inherit;
}

/* 主题色：星途蓝 + 萤窗金 */
:root {
    --primary: #4f46e5;
    --primary-dark: #4338ca;
    --primary-light: #818cf8;
    --accent: #f59e0b;
    --accent-light: #fbbf24;
    --bg-card: #ffffff;
    --bg-muted: #f1f5f9;
    --text: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --teacher-badge: #eab308;
}

/* 轻量星光/星星装饰：只做背景氛围 */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: 10;
    mix-blend-mode: screen;
    pointer-events: none;
    background:
        radial-gradient(2px 2px at 12% 18%, rgba(255, 255, 255, 0.7) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(1px 1px at 22% 42%, rgba(255, 255, 255, 0.6) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(1px 1px at 35% 24%, rgba(255, 255, 255, 0.55) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(2px 2px at 52% 16%, rgba(255, 255, 255, 0.6) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(1px 1px at 61% 38%, rgba(255, 255, 255, 0.55) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(2px 2px at 74% 22%, rgba(255, 255, 255, 0.65) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(1px 1px at 86% 44%, rgba(255, 255, 255, 0.55) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(1px 1px at 18% 70%, rgba(255, 255, 255, 0.55) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(2px 2px at 44% 78%, rgba(255, 255, 255, 0.6) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(1px 1px at 78% 74%, rgba(255, 255, 255, 0.55) 0%, rgba(255, 255, 255, 0) 60%);
    opacity: 0;
}

/* 第二层：更亮的星点 + 轻微闪烁，增强层次 */
body::after {
    content: "";
    position: fixed;
    inset: 0;
    z-index: 11;
    mix-blend-mode: screen;
    pointer-events: none;
    background:
        radial-gradient(3px 3px at 8% 18%, rgba(99, 102, 241, 0.95) 0%, rgba(99, 102, 241, 0) 62%),
        radial-gradient(2px 2px at 18% 26%, rgba(255, 255, 255, 1) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(2px 2px at 28% 66%, rgba(255, 255, 255, 0.95) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(2px 2px at 38% 42%, rgba(255, 255, 255, 0.88) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(4px 4px at 52% 18%, rgba(255, 255, 255, 1) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(2px 2px at 66% 54%, rgba(245, 158, 11, 0.85) 0%, rgba(245, 158, 11, 0) 62%),
        radial-gradient(3px 3px at 78% 30%, rgba(255, 255, 255, 0.95) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(2px 2px at 86% 74%, rgba(255, 255, 255, 0.9) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(5px 5px at 14% 78%, rgba(99, 102, 241, 0.95) 0%, rgba(99, 102, 241, 0) 62%),
        radial-gradient(2px 2px at 6% 54%, rgba(255, 255, 255, 0.78) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(3px 3px at 92% 38%, rgba(99, 102, 241, 0.8) 0%, rgba(99, 102, 241, 0) 62%),
        radial-gradient(2px 2px at 44% 76%, rgba(255, 255, 255, 0.8) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(3px 3px at 72% 62%, rgba(245, 158, 11, 0.55) 0%, rgba(245, 158, 11, 0) 62%),
        radial-gradient(2px 2px at 92% 72%, rgba(255, 255, 255, 0.85) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(4px 4px at 56% 80%, rgba(99, 102, 241, 0.75) 0%, rgba(99, 102, 241, 0) 62%),
        radial-gradient(2px 2px at 32% 88%, rgba(255, 255, 255, 0.85) 0%, rgba(255, 255, 255, 0) 60%),
        radial-gradient(3px 3px at 64% 10%, rgba(255, 255, 255, 0.8) 0%, rgba(255, 255, 255, 0) 60%);
    opacity: 0;
    animation: none;
    filter: saturate(1.2) brightness(1.08);
}

@keyframes starTwinkle {
    0%, 100% { opacity: 0.45; transform: translateY(0); }
    50% { opacity: 0.85; transform: translateY(-2px); }
}

@keyframes starDrift {
    0%, 100% {
        background-position: 8px 16px, 30px 10px, 0 0;
    }
    50% {
        background-position: 16px 8px, 22px 18px, 0 0;
    }
}

/* 顶部导航 */
.header {
    background: var(--bg-card);
    box-shadow: 0 2px 12px rgba(79, 70, 229, 0.08);
    padding: 0 24px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
}

.header-left { display: flex; align-items: center; }

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 22px;
    font-weight: 700;
    color: var(--primary);
    text-shadow: 0 10px 30px rgba(79, 70, 229, 0.18);
}

.logo i { font-size: 26px; color: var(--accent); }

.header-center {
    flex: 1;
    max-width: 400px;
    margin: 0 32px;
}

.search-box { position: relative; }

.search-box input {
    width: 100%;
    padding: 10px 16px 10px 40px;
    border: 2px solid var(--border);
    border-radius: 24px;
    font-size: 14px;
    background: var(--bg-muted);
    transition: all 0.3s ease;
}

.search-box input:focus {
    border-color: var(--primary);
    background: white;
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.search-box i {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

.header-right { display: flex; align-items: center; gap: 16px; }

.notification-icon {
    position: relative;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: background 0.3s;
}

.notification-icon:hover { background: var(--bg-muted); }

.notification-icon i { font-size: 20px; color: var(--text-muted); }

.notification-badge {
    position: absolute;
    top: 0;
    right: 0;
    background: #ef4444;
    color: white;
    border-radius: 50%;
    min-width: 18px;
    height: 18px;
    font-size: 11px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    padding: 6px 12px;
    border-radius: 24px;
    transition: background 0.3s;
}

.user-menu:hover { background: var(--bg-muted); }

.user-avatar {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 14px;
}

.user-name { font-weight: 500; color: var(--text); }

/* 认证教师黄色昵称 */
.nickname.verified { color: var(--teacher-badge); font-weight: 600; }

/* 主内容区 */
.main-content {
    margin-top: 64px;
    min-height: calc(100vh - 64px);
    max-width: 1400px;
    margin-left: auto;
    margin-right: auto;
    padding: 20px;
    position: relative;
    z-index: 5;
}

/* 有顶部主导航的页面：主内容下移为导航留出空间 */
body.has-top-nav .main-content {
    margin-top: 120px;
    min-height: calc(100vh - 120px);
}

/* 主导航（7 个入口）- 置于顶部，加深色以提醒 */
.bottom-nav {
    display: flex;
    justify-content: space-around;
    align-items: center;
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    bottom: auto;
    height: 56px;
    background: linear-gradient(135deg, #3730a3 0%, #312e81 50%, #1e1b4b 100%);
    box-shadow: 0 4px 16px rgba(0,0,0,0.25);
    z-index: 99;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    padding: 6px 12px;
    color: rgba(255,255,255,0.88);
    font-size: 11px;
    transition: color 0.3s, background 0.3s;
    border-radius: 8px;
}

.nav-item i { font-size: 20px; }

.nav-item:hover { color: #fff; background: rgba(255,255,255,0.12); }

.nav-item.active { color: #fff; font-weight: 600; background: rgba(255,255,255,0.18); }

/* 顶部 Tab 导航（页面内）*/
.top-nav {
    background: var(--bg-card);
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    padding: 0 16px;
    margin-bottom: 20px;
    border-radius: 12px;
    overflow: hidden;
}

.nav-tabs {
    display: flex;
    gap: 0;
    margin: 0;
    padding: 0;
    list-style: none;
}

.nav-tab {
    flex: 1;
    padding: 16px 20px;
    text-align: center;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-muted);
    background: transparent;
    border: none;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

.nav-tab:hover { background: var(--bg-muted); color: var(--primary); }

.nav-tab.active {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}

/* 按钮 */
.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    padding: 12px 24px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(79, 70, 229, 0.35);
}

.btn-secondary {
    background: white;
    color: var(--primary);
    padding: 12px 24px;
    border: 2px solid var(--primary);
    border-radius: 10px;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    cursor: pointer;
}

.btn-secondary:hover {
    background: var(--primary);
    color: white;
}

.btn-accent {
    background: linear-gradient(135deg, var(--accent), #d97706);
    color: white;
    padding: 12px 24px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-accent:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(245, 158, 11, 0.4);
}

/* 卡片 */
.card {
    background: var(--bg-card);
    border-radius: 16px;
    padding: 20px;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.08), 0 2px 4px -1px rgba(0,0,0,0.04);
    border: 1px solid var(--border);
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: 0 10px 20px -5px rgba(79, 70, 229, 0.1);
    transform: translateY(-2px);
}

.card-title { font-size: 16px; font-weight: 600; color: var(--text); margin-bottom: 4px; }

.card-subtitle { font-size: 13px; color: var(--text-muted); }

/* 资源/作品卡片（图文流）*/
.resource-card {
    background: var(--bg-card);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.resource-card:hover {
    box-shadow: 0 8px 20px rgba(79, 70, 229, 0.12);
    transform: translateY(-4px);
}

.resource-card .cover {
    width: 100%;
    aspect-ratio: 16/10;
    object-fit: cover;
    background: var(--bg-muted);
}

.resource-card .info { padding: 12px; }

.resource-card .title { font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 4px; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }

.resource-card .meta { font-size: 12px; color: var(--text-muted); display: flex; align-items: center; gap: 8px; margin-top: 6px; }

/* 输入框 */
.input-field {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: 10px;
    font-size: 14px;
    transition: all 0.3s ease;
    background: white;
}

.input-field:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.select-field {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: 10px;
    font-size: 14px;
    background: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

/* 模态框 */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(4px);
}

.modal-overlay.active { display: flex; }

.modal-content {
    background: white;
    border-radius: 20px;
    padding: 28px;
    max-width: 520px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.25);
    animation: modalIn 0.3s ease;
}

@keyframes modalIn {
    from { opacity: 0; transform: translateY(-20px) scale(0.98); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border);
}

.modal-header h3 { font-size: 18px; color: var(--text); font-weight: 600; }

.modal-close {
    font-size: 22px;
    cursor: pointer;
    color: var(--text-muted);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.modal-close:hover { color: var(--text); background: var(--bg-muted); }

/* 通知 */
.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    background: white;
    padding: 14px 20px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.12);
    z-index: 2000;
    display: none;
    align-items: center;
    gap: 10px;
    animation: slideIn 0.3s ease;
    border-left: 4px solid var(--primary);
}

.notification.active { display: flex; }

.notification.success { border-left-color: #22c55e; }

.notification.error { border-left-color: #ef4444; }

.notification.warning { border-left-color: var(--accent); }

.notification.info { border-left-color: var(--primary); }

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* 网格 */
.grid { display: grid; gap: 20px; }

.grid-2 { grid-template-columns: repeat(2, 1fr); }

.grid-3 { grid-template-columns: repeat(3, 1fr); }

.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* 用户下拉 */
.user-dropdown {
    position: absolute;
    top: 100%;
    right: 24px;
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    padding: 8px 0;
    min-width: 180px;
    display: none;
    z-index: 1000;
}

.user-dropdown.show { display: block; }

.dropdown-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    cursor: pointer;
    transition: background 0.3s;
    font-size: 14px;
}

.dropdown-item:hover { background: var(--bg-muted); }

.dropdown-divider { height: 1px; background: var(--border); margin: 6px 0; }

/* 个人中心 - 小红书风格 */
.profile-banner {
    height: 140px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 50%, #6366f1 100%);
    border-radius: 0 0 20px 20px;
    position: relative;
}

.profile-avatar-wrap {
    position: relative;
    margin-top: -48px;
    margin-bottom: 12px;
    padding-left: 20px;
}

.profile-avatar {
    width: 88px;
    height: 88px;
    border-radius: 50%;
    border: 4px solid white;
    object-fit: cover;
    background: var(--bg-muted);
}

.profile-name { font-size: 20px; font-weight: 700; color: var(--text); margin-bottom: 4px; }

.profile-bio { font-size: 13px; color: var(--text-muted); margin-bottom: 16px; }

.profile-stats {
    display: flex;
    gap: 24px;
    margin-bottom: 20px;
}

.profile-stat {
    text-align: center;
    cursor: pointer;
}

.profile-stat .num { font-size: 18px; font-weight: 700; color: var(--text); display: block; }

.profile-stat .label { font-size: 12px; color: var(--text-muted); }

/* 九宫格入口 */
.func-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.func-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 16px 8px;
    background: var(--bg-card);
    border-radius: 12px;
    border: 1px solid var(--border);
    cursor: pointer;
    transition: all 0.3s;
}

.func-item:hover {
    border-color: var(--primary);
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.15);
}

.func-item i { font-size: 24px; color: var(--primary); margin-bottom: 8px; }

.func-item span { font-size: 12px; color: var(--text); }

/* 标签 */
.tag {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    background: var(--bg-muted);
    color: var(--text-muted);
}

.tag-primary { background: rgba(79, 70, 229, 0.15); color: var(--primary); }

/* 分页/空状态 */
.empty-state {
    text-align: center;
    padding: 48px 20px;
    color: var(--text-muted);
}

.empty-state i { font-size: 48px; margin-bottom: 16px; opacity: 0.5; }

/* 响应式 */
@media (max-width: 1024px) {
    .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .func-grid { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 768px) {
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .func-grid { grid-template-columns: repeat(4, 1fr); gap: 12px; }
    .main-content { padding: 12px; }
    body.has-top-nav .main-content { margin-top: 116px; }
    .bottom-nav { height: 52px; }
    .nav-item span { display: none; }
}

/* 滚动条 */
::-webkit-scrollbar { width: 8px; height: 8px; }

::-webkit-scrollbar-track { background: var(--bg-muted); border-radius: 4px; }

::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 4px; }

::-webkit-scrollbar-thumb:hover { background: #94a3b8; }