/* ============================================================
   卡密授权验证平台 - 前台样式 style.css
   主色调：紫色渐变(#6366f1 → #8b5cf6)  辅助色：蓝色
   风格：现代时尚、圆角元素、类似新版QQ的简洁现代风格
   ============================================================ */

/* ============================================================
   1. CSS 变量与主题定义
   ============================================================ */
:root {
    /* 主色 - 紫色渐变 */
    --primary: #6366f1;
    --primary-light: #818cf8;
    --primary-dark: #4f46e5;
    --primary-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --primary-gradient-hover: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);

    /* 辅助色 - 蓝色 */
    --secondary: #3b82f6;
    --secondary-light: #60a5fa;
    --secondary-dark: #2563eb;

    /* 功能色 */
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;

    /* 中性色 */
    --text-primary: #1e293b;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --text-white: #ffffff;

    --bg-page: #f8fafc;
    --bg-card: #ffffff;
    --bg-overlay: rgba(15, 23, 42, 0.5);

    --border-color: #e2e8f0;
    --border-light: #f1f5f9;

    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
    --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 12px 32px rgba(15, 23, 42, 0.12);
    --shadow-xl: 0 24px 48px rgba(99, 102, 241, 0.18);

    /* 间距 */
    --container-max: 1200px;
    --navbar-height: 72px;

    /* 字体 */
    --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Microsoft YaHei", sans-serif;

    /* 过渡 */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================================
   2. 基础重置与全局样式
   ============================================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-stack);
    color: var(--text-primary);
    background-color: var(--bg-page);
    line-height: 1.6;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary-dark);
}

img {
    max-width: 100%;
    display: block;
}

ul, ol {
    list-style: none;
}

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

input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* ============================================================
   3. 通用按钮组件
   ============================================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 24px;
    font-size: 15px;
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: var(--transition);
    white-space: nowrap;
    border: 1px solid transparent;
    line-height: 1.4;
}

.btn-primary {
    background: var(--primary-gradient);
    color: var(--text-white);
    box-shadow: 0 4px 14px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    background: var(--primary-gradient-hover);
    color: var(--text-white);
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.4);
}

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

.btn-secondary:hover {
    border-color: var(--primary);
    background: rgba(99, 102, 241, 0.06);
    transform: translateY(-2px);
}

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

.btn-outline:hover {
    background: var(--primary);
    border-color: var(--primary);
    color: var(--text-white);
}

.btn-nav-login {
    background: transparent !important;
    color: var(--primary) !important;
    border-color: var(--primary) !important;
    font-weight: 500;
}

.btn-nav-login:hover {
    background: var(--primary) !important;
    color: #ffffff !important;
    border-color: var(--primary) !important;
}

.btn-lg {
    padding: 14px 32px;
    font-size: 16px;
}

.btn-sm {
    padding: 6px 16px;
    font-size: 13px;
}

.btn-block {
    width: 100%;
}

/* ============================================================
   4. 导航栏
   ============================================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--navbar-height);
    z-index: 1000;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(226, 232, 240, 0.6);
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 4px 20px rgba(15, 23, 42, 0.08);
}

.navbar-inner {
    height: 100%;
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.navbar-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
}

.navbar-logo .logo-icon {
    width: 36px;
    height: 36px;
    background: var(--primary-gradient);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    font-size: 18px;
}

.navbar-logo .logo-text {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.navbar-logo .logo-img {
    height: 36px;
    width: auto;
    display: block;
    border-radius: var(--radius-sm);
}

.footer .navbar-logo .logo-img-light {
    background: #fff;
    padding: 4px 8px;
    height: 32px;
}

.auth-logo .logo-img {
    height: 64px;
    width: auto;
    display: block;
}

.navbar-menu {
    display: flex;
    align-items: center;
    gap: 32px;
}

.navbar-menu a {
    color: var(--text-secondary);
    font-size: 15px;
    font-weight: 500;
    position: relative;
    padding: 8px 0;
}

.navbar-menu a:hover,
.navbar-menu a.active {
    color: var(--primary);
}

.navbar-menu a.active::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-gradient);
    border-radius: var(--radius-full);
}

.navbar-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.navbar-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.navbar-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: var(--transition);
}

/* ============================================================
   5. Hero 区域
   ============================================================ */
.hero {
    position: relative;
    padding: calc(var(--navbar-height) + 100px) 0 120px;
    background: linear-gradient(135deg, #f5f3ff 0%, #ede9fe 50%, #e0e7ff 100%);
    overflow: hidden;
}

.hero::before {
    content: "";
    position: absolute;
    top: -200px;
    right: -200px;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.25) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero::after {
    content: "";
    position: absolute;
    bottom: -200px;
    left: -200px;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.2) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero-inner {
    position: relative;
    z-index: 1;
    max-width: 820px;
    margin: 0 auto;
    text-align: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-full);
    color: var(--primary);
    font-size: 13px;
    font-weight: 500;
    margin-bottom: 24px;
}

.hero-title {
    font-size: 56px;
    font-weight: 800;
    line-height: 1.15;
    color: var(--text-primary);
    margin-bottom: 24px;
    letter-spacing: -0.02em;
}

.hero-title .gradient-text {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 19px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.7;
    max-width: 640px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-highlights {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 56px;
    flex-wrap: wrap;
}

.highlight-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    max-width: 240px;
}

.highlight-icon {
    width: 44px;
    height: 44px;
    flex-shrink: 0;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 20px;
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.15);
}

.highlight-text h4 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.highlight-text p {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.5;
    margin: 0;
}

/* ============================================================
   6. 通用区块标题
   ============================================================ */
.section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    max-width: 680px;
    margin: 0 auto 64px;
}

.section-title {
    font-size: 40px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
    letter-spacing: -0.01em;
}

.section-subtitle {
    font-size: 17px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================================
   7. 功能特性区
   ============================================================ */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 28px;
}

.feature-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary-gradient);
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.1));
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 26px;
    margin-bottom: 20px;
}

.feature-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.feature-desc {
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.7;
}

/* ============================================================
   8. 卡密类型展示区
   ============================================================ */
.card-types {
    background: linear-gradient(180deg, var(--bg-page) 0%, #f1f5f9 100%);
}

.card-types-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.card-type-item {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    transition: var(--transition);
}

.card-type-item:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}

.card-type-header {
    padding: 28px;
    background: var(--primary-gradient);
    color: var(--text-white);
    position: relative;
    overflow: hidden;
}

.card-type-header.blue {
    background: linear-gradient(135deg, #3b82f6 0%, #06b6d4 100%);
}

.card-type-header.green {
    background: linear-gradient(135deg, #10b981 0%, #14b8a6 100%);
}

.card-type-header.orange {
    background: linear-gradient(135deg, #f59e0b 0%, #f97316 100%);
}

.card-type-name {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 6px;
}

.card-type-tag {
    font-size: 13px;
    opacity: 0.9;
}

.card-type-body {
    padding: 28px;
}

.card-type-price {
    font-size: 32px;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.card-type-price .price-unit {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-muted);
}

.card-type-desc {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 20px;
    line-height: 1.6;
}

.card-type-features {
    margin-bottom: 24px;
}

.card-type-features li {
    padding: 8px 0;
    color: var(--text-secondary);
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.card-type-features li::before {
    content: "✓";
    width: 20px;
    height: 20px;
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
    border-radius: var(--radius-full);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 700;
    flex-shrink: 0;
}

/* ============================================================
   9. 统计数字区域
   ============================================================ */
.stats {
    background: var(--primary-gradient);
    color: var(--text-white);
    padding: 80px 0;
    position: relative;
    overflow: hidden;
}

.stats::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.1) 0%, transparent 40%),
        radial-gradient(circle at 80% 50%, rgba(255, 255, 255, 0.08) 0%, transparent 40%);
    pointer-events: none;
}

.stats-grid {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 32px;
    text-align: center;
}

.stat-item {
    padding: 20px;
}

.stat-number {
    font-size: 52px;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 8px;
    letter-spacing: -0.02em;
}

.stat-label {
    font-size: 16px;
    opacity: 0.9;
    font-weight: 500;
}

/* ============================================================
   10. 页脚
   ============================================================ */
.footer {
    background: #0f172a;
    color: #cbd5e1;
    padding: 64px 0 24px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-brand .navbar-logo {
    color: var(--text-white);
    margin-bottom: 16px;
}

.footer-brand p {
    color: #94a3b8;
    font-size: 14px;
    line-height: 1.7;
    max-width: 320px;
}

.footer-col h4 {
    color: var(--text-white);
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 20px;
}

.footer-col ul li {
    margin-bottom: 12px;
}

.footer-col ul li a {
    color: #94a3b8;
    font-size: 14px;
    transition: var(--transition);
}

.footer-col ul li a:hover {
    color: var(--primary-light);
    padding-left: 4px;
}

.footer-contact {
    display: flex;
    flex-direction: column;
    gap: 10px;
    color: #94a3b8;
    font-size: 14px;
}

.footer-contact span {
    display: flex;
    align-items: center;
    gap: 8px;
}

.footer-bottom {
    border-top: 1px solid rgba(148, 163, 184, 0.15);
    padding-top: 24px;
    text-align: center;
    color: #64748b;
    font-size: 14px;
}

/* ============================================================
   11. 认证页面（登录/注册）
   ============================================================ */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, #f5f3ff 0%, #ede9fe 50%, #e0e7ff 100%);
    position: relative;
    overflow: hidden;
}

.auth-page::before,
.auth-page::after {
    content: "";
    position: absolute;
    border-radius: 50%;
    pointer-events: none;
}

.auth-page::before {
    top: -150px;
    right: -150px;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.25), transparent 70%);
}

.auth-page::after {
    bottom: -150px;
    left: -150px;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.2), transparent 70%);
}

.auth-card {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 440px;
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    padding: 48px 40px;
}

.auth-card.auth-card-wide {
    max-width: 520px;
}

.auth-header {
    text-align: center;
    margin-bottom: 32px;
}

.auth-logo {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    background: var(--primary-gradient);
    border-radius: var(--radius-md);
    color: var(--text-white);
    font-size: 24px;
    margin-bottom: 20px;
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.3);
}

.auth-title {
    font-size: 26px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.auth-subtitle {
    color: var(--text-secondary);
    font-size: 15px;
}

/* ============================================================
   12. 表单组件
   ============================================================ */
.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 15px;
    transition: var(--transition);
    outline: none;
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: var(--text-muted);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.12);
}

.form-input.error,
.form-select.error,
.form-textarea.error {
    border-color: var(--danger);
}

.form-input.error:focus {
    box-shadow: 0 0 0 4px rgba(239, 68, 68, 0.12);
}

.form-textarea {
    min-height: 120px;
    resize: vertical;
}

.input-group {
    position: relative;
}

.input-group .form-input {
    padding-right: 48px;
}

.input-icon {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    cursor: pointer;
    font-size: 16px;
    transition: var(--transition);
}

.input-icon:hover {
    color: var(--primary);
}

.form-error {
    display: block;
    margin-top: 6px;
    color: var(--danger);
    font-size: 13px;
    min-height: 18px;
}

.form-hint {
    display: block;
    margin-top: 6px;
    color: var(--text-muted);
    font-size: 13px;
}

.form-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
    font-size: 14px;
}

.form-check {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    cursor: pointer;
}

.form-check input {
    width: 16px;
    height: 16px;
    accent-color: var(--primary);
    cursor: pointer;
}

.form-link {
    color: var(--primary);
    font-weight: 500;
}

.form-link:hover {
    color: var(--primary-dark);
}

.auth-divider {
    display: flex;
    align-items: center;
    gap: 16px;
    margin: 28px 0;
    color: var(--text-muted);
    font-size: 13px;
}

.auth-divider::before,
.auth-divider::after {
    content: "";
    flex: 1;
    height: 1px;
    background: var(--border-color);
}

.auth-footer {
    text-align: center;
    margin-top: 24px;
    color: var(--text-secondary);
    font-size: 14px;
}

/* ============================================================
   13. 密码强度指示器
   ============================================================ */
.password-strength {
    margin-top: 10px;
}

.strength-bar {
    display: flex;
    gap: 6px;
    margin-bottom: 6px;
}

.strength-bar span {
    flex: 1;
    height: 4px;
    background: var(--border-light);
    border-radius: var(--radius-full);
    transition: var(--transition);
}

.strength-bar.weak span:nth-child(1) { background: var(--danger); }
.strength-bar.fair span:nth-child(-n+2) { background: var(--warning); }
.strength-bar.good span:nth-child(-n+3) { background: var(--info); }
.strength-bar.strong span { background: var(--success); }

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

.strength-text.weak { color: var(--danger); }
.strength-text.fair { color: var(--warning); }
.strength-text.good { color: var(--info); }
.strength-text.strong { color: var(--success); }

/* ============================================================
   14. Toast 消息提示
   ============================================================ */
.toast-container {
    position: fixed;
    top: calc(var(--navbar-height) + 20px);
    right: 24px;
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 12px;
    pointer-events: none;
}

.toast {
    display: flex;
    align-items: center;
    gap: 12px;
    min-width: 280px;
    max-width: 400px;
    padding: 14px 18px;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    border-left: 4px solid var(--primary);
    pointer-events: auto;
    animation: toastSlideIn 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.toast.toast-out {
    animation: toastSlideOut 0.3s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

.toast-success { border-left-color: var(--success); }
.toast-warning { border-left-color: var(--warning); }
.toast-error { border-left-color: var(--danger); }
.toast-info { border-left-color: var(--info); }

.toast-icon {
    font-size: 18px;
    flex-shrink: 0;
}

.toast-success .toast-icon { color: var(--success); }
.toast-warning .toast-icon { color: var(--warning); }
.toast-error .toast-icon { color: var(--danger); }
.toast-info .toast-icon { color: var(--info); }

.toast-message {
    flex: 1;
    font-size: 14px;
    color: var(--text-primary);
}

.toast-close {
    color: var(--text-muted);
    font-size: 18px;
    line-height: 1;
    padding: 0 4px;
    transition: var(--transition);
}

.toast-close:hover {
    color: var(--text-primary);
}

@keyframes toastSlideIn {
    from { transform: translateX(120%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

@keyframes toastSlideOut {
    from { transform: translateX(0); opacity: 1; }
    to { transform: translateX(120%); opacity: 0; }
}

/* ============================================================
   15. 复制按钮与工具样式
   ============================================================ */
.copy-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    font-size: 13px;
    color: var(--primary);
    background: rgba(99, 102, 241, 0.08);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.copy-btn:hover {
    background: rgba(99, 102, 241, 0.15);
}

/* ============================================================
   16. 响应式设计
   ============================================================ */
@media (max-width: 992px) {
    .hero-title { font-size: 44px; }
    .section-title { font-size: 32px; }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}

@media (max-width: 768px) {
    .navbar-menu {
        position: fixed;
        top: var(--navbar-height);
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--bg-card);
        padding: 24px;
        gap: 16px;
        box-shadow: var(--shadow-lg);
        transform: translateY(-150%);
        transition: var(--transition);
        align-items: stretch;
    }

    .navbar-menu.open {
        transform: translateY(0);
    }

    .navbar-menu a {
        padding: 12px 16px;
        border-radius: var(--radius-sm);
    }

    .navbar-menu a.active::after { display: none; }

    .navbar-toggle { display: flex; }

    .navbar-actions .btn:not(.btn-primary) { display: none; }

    .hero { padding: calc(var(--navbar-height) + 60px) 0 80px; }
    .hero-title { font-size: 34px; }
    .hero-subtitle { font-size: 16px; }
    .hero-actions { flex-direction: column; }
    .hero-actions .btn { width: 100%; }

    .section { padding: 70px 0; }
    .section-title { font-size: 28px; }
    .section-header { margin-bottom: 40px; }

    .stat-number { font-size: 38px; }

    .footer-grid { grid-template-columns: 1fr; gap: 32px; }

    .auth-card { padding: 36px 24px; }
    .auth-title { font-size: 22px; }

    .toast-container { left: 16px; right: 16px; }
    .toast { min-width: 0; width: 100%; }

    .container { padding: 0 16px; }
}

@media (max-width: 480px) {
    .hero-title { font-size: 28px; }
    .feature-card { padding: 28px 20px; }
    .auth-card { padding: 28px 20px; }
}

/* ============================================================
   17. 工具类
   ============================================================ */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-gradient {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hidden { display: none !important; }
.mt-0 { margin-top: 0; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mb-0 { margin-bottom: 0; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }

/* 滚动条美化 */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--border-light); }
::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: var(--radius-full);
    border: 2px solid var(--border-light);
}
::-webkit-scrollbar-thumb:hover { background: var(--primary-light); }

/* 选中文本 */
::selection {
    background: rgba(99, 102, 241, 0.2);
    color: var(--primary-dark);
}

/* ============================================================
   18. 补充样式 - 登录/注册页面
   ============================================================ */

/* 表单输入框 (无.form-input类时也生效) */
.form-group input[type="text"],
.form-group input[type="password"],
.form-group input[type="email"] {
    width: 100%;
    padding: 12px 16px;
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 15px;
    transition: var(--transition);
    outline: none;
    font-family: inherit;
    box-sizing: border-box;
}

.form-group input[type="text"]:focus,
.form-group input[type="password"]:focus,
.form-group input[type="email"]:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.12);
}

.form-group input::placeholder {
    color: var(--text-muted);
}

/* 密码输入框容器 */
.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper input {
    width: 100%;
    padding: 12px 48px 12px 16px;
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 15px;
    transition: var(--transition);
    outline: none;
    font-family: inherit;
    box-sizing: border-box;
}

.input-wrapper input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.12);
}

.input-wrapper input::placeholder {
    color: var(--text-muted);
}

/* 密码可见性切换按钮 */
.toggle-password {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px 8px;
    font-size: 16px;
    transition: var(--transition);
}

.toggle-password:hover {
    color: var(--primary);
}

/* 提示框 */
.alert {
    padding: 12px 16px;
    border-radius: var(--radius-md);
    margin-bottom: 16px;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.alert-success {
    background: #f0fdf4;
    color: #16a34a;
    border: 1px solid #bbf7d0;
}

.alert-error {
    background: #fef2f2;
    color: #dc2626;
    border: 1px solid #fecaca;
}

.alert-info {
    background: #eff6ff;
    color: #2563eb;
    border: 1px solid #bfdbfe;
}

/* 密码强度指示器 */
.password-strength {
    margin-top: 8px;
    height: 4px;
    border-radius: var(--radius-full);
    background: var(--border-light);
    overflow: hidden;
}

.password-strength::after {
    content: '';
    display: block;
    height: 100%;
    width: 0;
    border-radius: var(--radius-full);
    transition: var(--transition);
}

.password-strength.weak::after {
    width: 25%;
    background: #ef4444;
}

.password-strength.fair::after {
    width: 50%;
    background: #f59e0b;
}

.password-strength.good::after {
    width: 75%;
    background: #3b82f6;
}

.password-strength.strong::after {
    width: 100%;
    background: #10b981;
}

/* ============================================================
   19. 快速接入流程样式
   ============================================================ */
.process-section {
    padding: 80px 0;
    background: var(--bg-page);
}

.process-steps {
    display: flex;
    align-items: stretch;
    justify-content: center;
    gap: 24px;
    flex-wrap: wrap;
}

.process-step {
    flex: 1;
    min-width: 260px;
    max-width: 320px;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    position: relative;
    display: flex;
    flex-direction: column;
}

.process-step:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-md);
}

.step-number {
    font-size: 56px;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
    line-height: 1;
}

.process-step h3 {
    font-size: 20px;
    color: var(--text-primary);
    margin-bottom: 12px;
    font-weight: 700;
}

.process-step p {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.7;
    flex: 1;
}

.process-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-top: 20px;
    color: var(--primary);
    font-size: 14px;
    font-weight: 600;
    transition: var(--transition);
}

.process-link:hover {
    gap: 10px;
    color: var(--primary-dark);
}

.process-arrow {
    display: flex;
    align-items: center;
    color: var(--border-color);
    font-size: 24px;
    flex-shrink: 0;
}

@media (max-width: 992px) {
    .process-arrow { display: none; }
    .process-steps { flex-direction: column; align-items: center; }
    .process-step { max-width: 400px; }
}

/* ============================================================
   20. 常见问题样式优化
   ============================================================ */
.faq-section {
    padding: 80px 0;
    background: var(--bg-card);
}

.faq-list {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.faq-item {
    background: var(--bg-page);
    border-radius: var(--radius-md);
    padding: 24px 28px;
    transition: var(--transition);
    border: 1px solid var(--border-light);
}

.faq-item:hover {
    border-color: var(--primary-light);
    box-shadow: 0 4px 16px rgba(99, 102, 241, 0.08);
}

.faq-item h4 {
    font-size: 16px;
    color: var(--text-primary);
    margin-bottom: 10px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 10px;
}

.faq-item h4::before {
    content: "Q";
    width: 26px;
    height: 26px;
    background: var(--primary-gradient);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    font-weight: 700;
    flex-shrink: 0;
}

.faq-item p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.8;
    padding-left: 36px;
    margin: 0;
}