:root {
    --bg-gradient-1: #0f172a;
    --bg-gradient-2: #1e1b4b;
    --bg-gradient-3: #022c22;
    --card-bg: rgba(30, 41, 59, 0.6);
    --card-border: rgba(255, 255, 255, 0.1);
    --text-main: #ffffff;
    --text-muted: #94a3b8;
    --accent-color: #38bdf8;
    --accent-hover: #0ea5e9;
    --danger-color: #ef4444;
    --success-color: #10b981;
    --font-sans: 'Inter', system-ui, sans-serif;
    --font-heading: 'Outfit', sans-serif;
    --font-mono: 'Space Mono', monospace;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html, body {
    width: 100vw;
    height: 100vh;
    overflow: hidden; /* 防止移动端任何意外的滑动 */
    overscroll-behavior: none; /* 禁用系统级下拉刷新回调 */
}

body {
    font-family: var(--font-sans);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    background: linear-gradient(135deg, var(--bg-gradient-1), var(--bg-gradient-2), var(--bg-gradient-3));
    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%; }
}

.background-effect {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 150vw;
    height: 150vh;
    background: 
        radial-gradient(circle at 20% 30%, rgba(56, 189, 248, 0.15), transparent 40%),
        radial-gradient(circle at 80% 70%, rgba(16, 185, 129, 0.15), transparent 40%);
    z-index: 0;
    pointer-events: none;
    animation: pulse 12s ease-in-out infinite alternate;
}

@keyframes pulse {
    0% { transform: translate(-50%, -50%) scale(1); opacity: 0.6; }
    100% { transform: translate(-50%, -50%) scale(1.1); opacity: 1; }
}

.container {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 440px;
    padding: 20px;
}

/* 毛玻璃卡片 */
.glass-card {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--card-border);
    border-radius: 24px;
    padding: 32px 40px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

.glass-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 30px 60px -12px rgba(0, 0, 0, 0.6);
}

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

header h1 {
    font-family: var(--font-heading);
    font-size: 26px;
    font-weight: 700;
    margin-bottom: 8px;
    background: linear-gradient(to right, #4facfe 0%, #00f2fe 100%);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.5px;
}

header p {
    color: var(--text-muted);
    font-size: 14px;
}

/* 隐藏在视图之外的系统提示，供 JS 统一调用 */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: rgba(16, 185, 129, 0.9); /* 使用 success-color 近似值 */
    color: white;
    padding: 12px 24px;
    border-radius: 30px;
    font-size: 14px;
    font-weight: 500;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
    opacity: 0;
    pointer-events: none;
    transition: all 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    backdrop-filter: blur(8px);
    z-index: 9999;
    white-space: nowrap;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

@media (max-width: 480px) {
    .glass-card {
        padding: 24px;
    }
}