/* ========== CSS 变量 ========== */
:root {
    --primary: #1a5fb4;
    --primary-dark: #0d3b7a;
    --accent: #e66100;
    --bg: #f0f2f5;
    --card-bg: #ffffff;
    --text: #1c1c1c;
    --text-secondary: #5e5e5e;
    --border: #d0d5dd;
    --success: #2ec27e;
    --warning: #f5c211;
    --danger: #e01b24;
}

/* ========== 基础重置 ========== */
* { margin: 0; padding: 0; box-sizing: border-box; }

html, body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
    background: var(--bg);
    color: var(--text);
    height: 100%;
    width: 100%;
    overflow-x: hidden;
}

/* ========== 顶部栏 ========== */
.top-bar {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: 50px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 30px;
    z-index: 1000;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.logo {
    font-size: 16px;
    font-weight: 700;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
}

.logo-icon {
    width: 28px; height: 28px;
    background: var(--primary);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 14px;
}

.page-indicator {
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* ========== 进度条 ========== */
.progress-container {
    position: fixed;
    top: 50px; left: 0; right: 0;
    height: 4px;
    background: #e4e7ec;
    z-index: 999;
}

.progress-bar {
    height: 100%;
    background: var(--primary);
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    width: 0%;
}

/* ========== 页面容器 ========== */
.page-container {
    position: relative;
    width: 100%;
    min-height: 100vh;
    padding-top: 54px;
    padding-bottom: 24px;
    display: flex;
    flex-direction: column;
}

.page-content {
    flex: 1;
    padding: 40px 60px;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    display: flex;
    flex-direction: column;
}

/* ========== 页面标题 ========== */
.page-title {
    font-size: 36px;
    font-weight: 800;
    color: var(--primary-dark);
    margin-bottom: 8px;
    letter-spacing: -0.5px;
}

.page-subtitle {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--border);
}

/* ========== 底部控制栏 ========== */
.bottom-bar {
    display: none !important;
}

.nav-btn {
    width: 44px; height: 44px;
    border-radius: 50%;
    border: 2px solid var(--border);
    background: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    color: var(--text);
    text-decoration: none;
    transition: all 0.2s;
}

.nav-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: scale(1.1);
}

.nav-btn.disabled {
    opacity: 0.3;
    cursor: not-allowed;
    pointer-events: none;
    transform: none;
}

.dots {
    display: flex;
    gap: 10px;
}

.dot {
    width: 10px; height: 10px;
    border-radius: 50%;
    background: var(--border);
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: block;
}

.dot.active {
    background: var(--primary);
    width: 28px;
    border-radius: 5px;
}

/* ========== 键盘提示 ========== */
.keyboard-hint {
    position: fixed;
    bottom: 22px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(0,0,0,0.7);
    color: white;
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 12px;
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
    z-index: 1001;
}

.keyboard-hint.show {
    opacity: 1;
}

/* ========== 通用卡片 ========== */
.card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 24px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.08);
    border: 1px solid var(--border);
    margin-bottom: 20px;
}

.card-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.side-nav {
    position: fixed;
    top: 84px;
    left: 16px;
    right: 16px;
    bottom: 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    pointer-events: none;
    z-index: 1000;
}

.side-nav-btn {
    width: 76px;
    min-height: 168px;
    border-radius: 28px;
    border: 2px solid rgba(208, 213, 221, 0.95);
    background: rgba(255,255,255,0.96);
    box-shadow: 0 14px 34px rgba(13, 59, 122, 0.12);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
    color: var(--primary-dark);
    text-decoration: none;
    pointer-events: auto;
    transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
    backdrop-filter: blur(4px);
}

.side-nav-btn:hover {
    transform: translateY(-2px);
    border-color: var(--primary);
    box-shadow: 0 18px 40px rgba(13, 59, 122, 0.18);
}

.side-nav-btn.disabled {
    opacity: 0.35;
    pointer-events: none;
    box-shadow: none;
}

.side-nav-arrow {
    font-size: 34px;
    font-weight: 800;
    line-height: 1;
}

.side-nav-text {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    text-align: center;
}

.side-nav-main {
    font-size: 13px;
    font-weight: 700;
}

.side-nav-sub {
    font-size: 10px;
    color: var(--text-secondary);
}

.en-sub {
    display: block;
    margin-top: 4px;
    color: var(--text-secondary);
    font-size: 12px;
    line-height: 1.45;
    font-weight: 500;
}

.page-title .en-sub {
    font-size: 16px;
    line-height: 1.35;
    margin-top: 6px;
}

.page-subtitle .en-sub {
    font-size: 13px;
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
    .page-content { padding: 30px 30px; }
    .page-title { font-size: 28px; }
}

@media (max-width: 640px) {
    .page-content { padding: 20px 16px; }
    .page-title { font-size: 24px; }
    .top-bar { padding: 0 16px; }
    .logo span { display: none; }
    .side-nav {
        top: auto;
        left: 10px;
        right: 10px;
        bottom: 90px;
    }
    .side-nav-btn {
        width: 62px;
        min-height: 118px;
        border-radius: 22px;
    }
    .side-nav-arrow { font-size: 28px; }
    .side-nav-main { font-size: 11px; }
    .side-nav-sub { font-size: 9px; }
}