* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'PingFang SC', 'Inter', Roboto, system-ui, sans-serif;
}

body {
    min-height: 100vh;
    background: linear-gradient(145deg, #0b1120 0%, #19223a 70%, #1c2a44 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    position: relative;
    overflow-x: hidden;
}

/* 动态背景光效 */
body::before {
    content: '';
    position: absolute;
    width: 120%;
    height: 120%;
    background: radial-gradient(circle at 30% 40%, rgba(100, 150, 255, 0.15) 0%, transparent 40%),
                radial-gradient(circle at 80% 70%, rgba(255, 200, 100, 0.1) 0%, transparent 40%);
    top: -10%;
    left: -10%;
    z-index: 0;
    animation: breath 12s ease-in-out infinite alternate;
}

@keyframes breath {
    0% { opacity: 0.5; transform: scale(1); }
    100% { opacity: 1; transform: scale(1.05); }
}

.card {
    position: relative;
    z-index: 10;
    max-width: 720px;
    width: 100%;
    background: rgba(18, 26, 40, 0.65);
    backdrop-filter: blur(12px) saturate(180%);
    -webkit-backdrop-filter: blur(12px) saturate(180%);
    border-radius: 3rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 35px 75px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(120, 180, 255, 0.2) inset;
    padding: 2.8rem 2.5rem;
    transition: box-shadow 0.3s ease;
}

/* 时间展示区 */
.time-show {
    text-align: center;
    margin-bottom: 3.2rem;
}

/* 时间显示 */
.clock {
    font-size: 6rem;
    font-weight: 700;
    color: #ffffff;
    text-shadow: 0 0 20px #3b7fd9, 0 0 40px #1e4f9e;
    letter-spacing: 8px;
    line-height: 1.1;
    font-variant-numeric: tabular-nums;
    margin-bottom: 0.8rem;
}

/* 冒号独立样式，用于闪烁 */
.clock .colon {
    display: inline-block;
    transition: all 0.1s ease;
}

/* 闪烁动画 */
@keyframes colonFlash {
    0% { text-shadow: 0 0 20px #3b7fd9; }
    50% { text-shadow: 0 0 40px #7fb9ff, 0 0 80px #3f8aff; transform: scale(1.1); }
    100% { text-shadow: 0 0 20px #3b7fd9; }
}

.colon-flash {
    animation: colonFlash 0.2s ease-out;
}

.date {
    font-size: 2.4rem;
    font-weight: 400;
    color: #ffffff;
    text-shadow: 0 2px 15px #2d6bb0;
    letter-spacing: 2px;
    line-height: 1.3;
}

.weekday {
    font-size: 1.6rem;
    color: #ccdeff;
    margin-left: 15px;
    font-weight: 350;
    text-shadow: 0 0 15px #3f88ff;
}

/* 按钮组 */
.button-group {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 1.2rem;
    margin: 3rem 0 0;
}

.aurora-btn {
    position: relative;
    padding: 0.9rem 2rem;
    border: none;
    background: rgba(25, 40, 60, 0.7);
    backdrop-filter: blur(8px);
    border-radius: 50px;
    font-size: 1.3rem;
    font-weight: 550;
    color: #f0f5ff;
    cursor: pointer;
    transition: all 0.25s ease;
    box-shadow: 0 5px 15px rgba(0, 10, 30, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.08);
    letter-spacing: 1px;
    min-width: 120px;
    text-align: center;
}

.aurora-btn:hover {
    background: linear-gradient(145deg, #3f4b8c, #2c3a6e);
    border-color: #b0baff;
    animation: auroraFloat 2.2s infinite ease-in-out;
    box-shadow: 0 15px 30px -5px #6f8cff;
    color: #ffffff;
}

@keyframes auroraFloat {
    0% { transform: translateY(0); }
    50% { transform: translateY(-6px); }
    100% { transform: translateY(0); }
}

/* 按钮颜色微调 */
.btn-1:hover { background: linear-gradient(145deg, #4a589e, #35437c); }
.btn-2:hover { background: linear-gradient(145deg, #5d4f9a, #3f3173); }
.btn-3:hover { background: linear-gradient(145deg, #3e6b9e, #274a73); }
.btn-4:hover { background: linear-gradient(145deg, #6b4f9e, #443773); }
.btn-5:hover { background: linear-gradient(145deg, #9e4f7a, #73375a); }
.btn-6:hover { background: linear-gradient(145deg, #4f7a9e, #315573); }

/* 响应式设计 */
@media (max-width: 500px) {
    .card { padding: 2rem 1.2rem; }
    .clock { font-size: 4.2rem; letter-spacing: 4px; }
    .date { font-size: 1.8rem; }
    .weekday { font-size: 1.3rem; }
    .aurora-btn { min-width: 100px; padding: 0.7rem 1.2rem; font-size: 1.1rem; }
}