/**
 * Common Styles - 通用基础样式
 * 元思维交互式编程学习平台
 */

/* ===== 重置与基础 ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
}

/* ===== 渐变背景 ===== */
.gradient-bg {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 50%, #1e1b4b 100%);
}

.bg-gradient-animated {
    background: linear-gradient(-45deg, #0a0f1a, #1a1f3a, #0f2027, #1a1a2e);
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* ===== 玻璃态效果 ===== */
.glass {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--border-default);
}

.glass-strong {
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-default);
}

/* ===== 渐变文字 ===== */
.text-gradient {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 50%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.text-gradient-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.text-gradient-light {
    background: linear-gradient(135deg, #ffffff 0%, #94a3b8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===== 链接样式 ===== */
a {
    color: inherit;
    text-decoration: none;
    transition: var(--transition-fast);
}

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

/* ===== 选中样式 ===== */
::selection {
    background: rgba(var(--primary-rgb), 0.3);
    color: var(--text-primary);
}

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

::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* ===== 工具类 ===== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ===== 粒子背景 ===== */
.particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 0;
    pointer-events: none;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: rgba(var(--primary-rgb), 0.3);
    border-radius: 50%;
    animation: particleFloat 20s infinite;
    will-change: transform, opacity;
}

@keyframes particleFloat {
    0%, 100% {
        transform: translateY(100vh) rotate(0deg);
        opacity: 0;
    }
    10% { opacity: 1; }
    90% { opacity: 1; }
    100% {
        transform: translateY(-100vh) rotate(720deg);
        opacity: 0;
    }
}

/* 减少动画 */
@media (prefers-reduced-motion: reduce) {
    .particle,
    .bg-gradient-animated {
        animation: none;
    }
}

/* ===== 光晕效果 ===== */
.glow-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    animation: pulseGlow 8s ease-in-out infinite;
    will-change: transform, opacity;
    pointer-events: none;
}

@keyframes pulseGlow {
    0%, 100% {
        transform: scale(1);
        opacity: 0.3;
    }
    50% {
        transform: scale(1.2);
        opacity: 0.5;
    }
}

@media (prefers-reduced-motion: reduce) {
    .glow-orb {
        animation: none;
    }
}

/* ===== 代码装饰 ===== */
.code-decoration {
    font-family: var(--font-mono);
    color: var(--primary);
    opacity: 0.1;
    font-size: 12px;
    line-height: 1.4;
    white-space: pre;
    position: absolute;
    pointer-events: none;
    user-select: none;
}

/* ===== 入场动画 ===== */
.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease forwards;
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }
.delay-5 { animation-delay: 0.5s; }

@media (prefers-reduced-motion: reduce) {
    .fade-in-up {
        opacity: 1;
        transform: none;
        animation: none;
    }
}

/* ===== 加载动画 ===== */
.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-default);
    border-top-color: var(--secondary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 300px;
    gap: var(--spacing-md);
}

/* ===== 响应式隐藏 ===== */
@media (max-width: 640px) {
    .hidden-mobile { display: none !important; }
}

@media (min-width: 641px) {
    .hidden-desktop { display: none !important; }
}

@media (max-width: 768px) {
    .hidden-tablet { display: none !important; }
}