:root {
    --bg: #eef3ff;
    --surface: rgba(255, 255, 255, 0.92);
    --surface-solid: #ffffff;
    --surface-soft: #f5f8ff;
    --surface-strong: #ebf1ff;
    --surface-tint: #f8fbff;
    --text: #20314f;
    --text-muted: #62779f;
    --text-soft: #8a9ab9;
    --primary: #2e63ff;
    --primary-soft: #eaf0ff;
    --primary-strong: #1b49d0;
    --accent: #1db6d9;
    --accent-soft: rgba(29, 182, 217, 0.14);
    --border: rgba(163, 183, 235, 0.38);
    --border-strong: rgba(115, 142, 211, 0.32);
    --success: #179a74;
    --warning: #c9830a;
    --danger: #d64a5f;
    --shadow-sm: 0 10px 24px rgba(42, 69, 144, 0.08);
    --shadow-md: 0 18px 40px rgba(32, 61, 140, 0.12);
    --shadow-lg: 0 30px 80px rgba(25, 47, 108, 0.16);
    --radius-sm: 12px;
    --radius-md: 18px;
    --radius-lg: 30px;
    --radius-pill: 999px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    color: var(--text);
    font-family: 'Segoe UI', 'Microsoft YaHei', 'PingFang SC', 'Noto Sans SC', sans-serif;
    background:
        radial-gradient(circle at 12% 18%, rgba(46, 99, 255, 0.18), transparent 24%),
        radial-gradient(circle at 88% 14%, rgba(29, 182, 217, 0.18), transparent 22%),
        radial-gradient(circle at 50% 100%, rgba(125, 146, 255, 0.12), transparent 28%),
        linear-gradient(180deg, #f8fbff 0%, #eef3ff 48%, #edf2ff 100%);
    position: relative;
}

body::before,
body::after {
    content: '';
    position: fixed;
    inset: 0;
    pointer-events: none;
}

body::before {
    opacity: 0.3;
    background-image:
        linear-gradient(rgba(102, 129, 197, 0.06) 1px, transparent 1px),
        linear-gradient(90deg, rgba(102, 129, 197, 0.06) 1px, transparent 1px);
    background-size: 32px 32px;
    mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.85), transparent 92%);
}

body::after {
    background:
        radial-gradient(circle at 18% 24%, rgba(255, 255, 255, 0.75), transparent 22%),
        radial-gradient(circle at 78% 12%, rgba(255, 255, 255, 0.7), transparent 18%);
}

.container {
    width: min(1540px, calc(100vw - 32px));
    max-width: none;
    margin: 14px auto 24px;
    position: relative;
    z-index: 1;
}

.card {
    border: 1px solid rgba(255, 255, 255, 0.72);
    border-radius: var(--radius-lg);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(248, 251, 255, 0.96));
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    backdrop-filter: blur(18px);
}

.card-header {
    border: 0;
    padding: 20px 24px 18px;
    text-align: center;
    background:
        radial-gradient(circle at 16% 50%, rgba(255, 255, 255, 0.24), transparent 36%),
        radial-gradient(circle at 84% 24%, rgba(255, 255, 255, 0.16), transparent 22%),
        linear-gradient(135deg, #2456f4 0%, #4d79ff 48%, #18b8d7 100%);
    color: #fff;
    position: relative;
    isolation: isolate;
}

.card-header::after {
    content: '';
    position: absolute;
    inset: auto 24px 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.55), transparent);
}

.hero-eyebrow {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 8px;
    padding: 6px 12px;
    border: 1px solid rgba(255, 255, 255, 0.22);
    border-radius: var(--radius-pill);
    background: rgba(255, 255, 255, 0.14);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.18);
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

.card-header h2 {
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    font-family: 'Noto Serif SC', 'STSong', 'SimSun', serif;
    letter-spacing: 0.04em;
    font-weight: 400;
    font-size: clamp(2rem, 1.7rem + 0.7vw, 2.55rem);
    text-shadow: 0 10px 24px rgba(13, 28, 84, 0.18);
}

.card-header h2 i {
    font-size: 0.9em;
}

.hero-subtitle {
    width: min(760px, 100%);
    margin: 8px auto 0;
    color: rgba(255, 255, 255, 0.86);
    font-size: 0.98rem;
    line-height: 1.65;
    letter-spacing: 0.01em;
}

.card-body {
    padding: 22px;
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.12), transparent 80%),
        linear-gradient(180deg, rgba(248, 251, 255, 0.85), rgba(245, 248, 255, 0.96));
}

.tab-pane {
    animation: paneFade 0.24s ease;
}

@keyframes paneFade {
    from {
        opacity: 0;
        transform: translateY(4px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.instructions {
    position: relative;
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(244, 248, 255, 0.98)),
        radial-gradient(circle at 100% 0%, rgba(46, 99, 255, 0.08), transparent 32%);
    border: 1px solid rgba(163, 183, 235, 0.32);
    border-radius: 22px;
    padding: 18px 20px 18px 22px;
    color: #435a86;
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.instructions::before {
    content: '';
    position: absolute;
    inset: 12px auto 12px 0;
    width: 4px;
    border-radius: 0 999px 999px 0;
    background: linear-gradient(180deg, var(--primary), var(--accent));
}

.instructions h5 {
    margin: 0 0 12px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: #2f57c2;
    font-size: 0.96rem;
    font-weight: 780;
    letter-spacing: 0.01em;
}

.instructions h5 i {
    color: var(--accent);
}

.instructions ul {
    margin: 0;
    padding-left: 1.2rem;
}

.instructions li {
    margin-bottom: 7px;
    line-height: 1.58;
}

.instructions li:last-child {
    margin-bottom: 0;
}