/* ============================================
   Transmit 中文官网 - 公共样式
   主题色: #383838 #7083FF
   浅色主题
   ============================================ */

/* CSS Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-primary: #7083FF;
    --color-primary-light: #8a9aff;
    --color-primary-dark: #5a6de6;
    --color-dark: #383838;
    --color-dark-light: #555555;
    --color-text: #333333;
    --color-text-secondary: #666666;
    --color-text-light: #999999;
    --color-bg: #ffffff;
    --color-bg-light: #f8f9fc;
    --color-bg-gray: #f0f2f5;
    --color-border: #e8eaed;
    --color-border-light: #f0f0f0;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.12);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", "Courier New", monospace;
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-slow: 0.4s ease;
    --max-width: 1200px;
    --nav-height: 72px;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.8;
    overflow-x: hidden;
}

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

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

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

h1, h2, h3, h4, h5, h6 {
    color: var(--color-dark);
    line-height: 1.4;
    font-weight: 700;
}

h1 { font-size: 2.8rem; }
h2 { font-size: 2.2rem; }
h3 { font-size: 1.6rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: 1rem;
    line-height: 1.8;
}

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

/* Utility Classes */
.text-center { text-align: center; }
.text-primary { color: var(--color-primary); }
.text-dark { color: var(--color-dark); }
.text-secondary { color: var(--color-text-secondary); }
.text-light { color: var(--color-text-light); }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all var(--transition-normal);
    text-decoration: none;
    line-height: 1.4;
    white-space: nowrap;
}

.btn svg {
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(112, 131, 255, 0.35);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary));
    color: #ffffff;
    box-shadow: 0 6px 20px rgba(112, 131, 255, 0.45);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    color: var(--color-dark-light);
    border: 1.5px solid var(--color-border);
}

.btn-outline:hover {
    color: var(--color-primary);
    border-color: var(--color-primary);
    background: rgba(112, 131, 255, 0.04);
}

/* Section Styles */
.section {
    padding: 80px 0;
}

.section-alt {
    background-color: var(--color-bg-light);
}

.section-title {
    font-size: 2.2rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--color-dark);
}

.section-subtitle {
    font-size: 1.1rem;
    text-align: center;
    color: var(--color-text-secondary);
    max-width: 700px;
    margin: 0 auto 3rem;
    line-height: 1.8;
}

/* Card Styles */
.card {
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border-light);
    transition: all var(--transition-normal);
}

.card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

/* Fade-in animation */
.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Selection */
::selection {
    background: rgba(112, 131, 255, 0.15);
    color: var(--color-dark);
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-light);
}

::-webkit-scrollbar-thumb {
    background: #ccc;
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: #aaa;
}

/* Responsive */
@media (max-width: 1024px) {
    h1 { font-size: 2.2rem; }
    h2 { font-size: 1.8rem; }
    .section { padding: 60px 0; }
    .section-title { font-size: 1.8rem; }
}

@media (max-width: 768px) {
    html { font-size: 15px; }
    h1 { font-size: 1.8rem; }
    h2 { font-size: 1.5rem; }
    .section { padding: 48px 0; }
    .container { padding: 0 16px; }
    .section-title { font-size: 1.6rem; }
    .section-subtitle { font-size: 1rem; }
}

@media (max-width: 480px) {
    html { font-size: 14px; }
    h1 { font-size: 1.6rem; }
    .section { padding: 36px 0; }
    .btn { padding: 10px 20px; font-size: 0.9rem; }
}