:root {
    --bg: #05070d;
    --text-main: #eff3ff;
    --text-dim: rgba(239, 243, 255, 0.68);
    --line: rgba(239, 243, 255, 0.22);
    --accent-a: #8ab4ff;
    --accent-b: #ff9acb;
    --gold: #d7c289;
    --gold-dim: rgba(215, 194, 137, 0.7);
    --cert-bg: rgba(7, 12, 24, 0.92);
}

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

body {
    font-family: "Manrope", "Helvetica Neue", Arial, sans-serif;
    background:
        radial-gradient(circle at 20% 20%, rgba(138, 180, 255, 0.08), transparent 35%),
        radial-gradient(circle at 80% 15%, rgba(255, 154, 203, 0.08), transparent 30%),
        var(--bg);
    color: var(--text-main);
    overflow-x: hidden;
    text-rendering: optimizeLegibility;
}

#lang-switcher {
    position: fixed;
    top: 16px;
    right: 16px;
    z-index: 30;
    display: inline-flex;
    gap: 8px;
    padding: 6px;
    border: 1px solid rgba(239, 243, 255, 0.2);
    border-radius: 999px;
    backdrop-filter: blur(6px);
    background: rgba(7, 12, 24, 0.45);
}

.lang-btn {
    border: 0;
    border-radius: 999px;
    padding: 6px 10px;
    background: transparent;
    color: var(--text-dim);
    font: inherit;
    font-size: 0.85rem;
    cursor: pointer;
}

.lang-btn.active {
    background: rgba(239, 243, 255, 0.14);
    color: var(--text-main);
}

/* 星空 canvas */
#starfield {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
}

/* 每一幕 */
.scene {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 48px 28px;
}

.content {
    max-width: 760px;
}

#scene-4,
#scene-5 {
    min-height: 90vh;
}

h1 {
    font-family: "Playfair Display", Georgia, serif;
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 400;
    letter-spacing: 0.01em;
}

h2 {
    font-family: "Playfair Display", Georgia, serif;
    font-size: clamp(1.6rem, 3.2vw, 2.2rem);
    margin: 20px 0 10px;
    font-weight: 400;
}

p {
    margin-bottom: 20px;
    line-height: 1.6;
    font-weight: 300;
    color: var(--text-dim);
}

.small {
    font-size: 14px;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--text-dim);
}

.caption {
    color: var(--text-dim);
    margin-top: 30px;
    font-size: 14px;
    letter-spacing: 0.03em;
}

.counter-placeholder {
    margin-top: 44px;
    font-size: 18px;
}

#counter {
    margin-top: 10px;
    font-size: clamp(1.1rem, 2.8vw, 1.6rem);
    font-weight: 500;
    line-height: 1.4;
    color: var(--text-main);
}

.milestones {
    margin-top: 34px;
    border-top: 1px solid var(--line);
    padding-top: 22px;
}

.milestones p {
    margin-bottom: 8px;
    letter-spacing: 0.02em;
}

.milestones span {
    display: inline-block;
    min-width: 110px;
    color: var(--text-main);
    font-weight: 500;
}

.scene {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 1.2s ease, transform 1.2s ease;
}

.scene.visible {
    opacity: 1;
    transform: translateY(0);
}

#intro-overlay {
    position: fixed;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(circle at 50% 20%, rgba(138, 180, 255, 0.08), transparent 35%),
        #000;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    transition: opacity 2s ease;
}

.intro-text {
    font-size: 20px;
    opacity: 0.8;
    text-align: center;
    font-weight: 300;
    line-height: 1.6;
}

#intro-overlay.fade-out {
    opacity: 0;
    pointer-events: none;
}

.final-line {
    font-size: clamp(1.1rem, 2.8vw, 1.6rem);
    color: var(--text-main);
    margin-top: 24px;
}

#certificate {
    margin: 32px auto 0;
    width: min(760px, 100%);
    text-align: left;
    border: 1px solid rgba(215, 194, 137, 0.35);
    background:
        radial-gradient(circle at 80% 25%, rgba(215, 194, 137, 0.08), transparent 32%),
        var(--cert-bg);
    padding: 26px 24px;
    border-radius: 14px;
    position: relative;
    overflow: hidden;
}

.cert-header {
    border-bottom: 1px solid rgba(215, 194, 137, 0.26);
    margin-bottom: 18px;
    padding-bottom: 16px;
}

.cert-header h3 {
    font-family: "Playfair Display", Georgia, serif;
    font-size: 1.45rem;
    font-weight: 500;
    color: var(--gold);
}

.cert-header p {
    margin-top: 8px;
    margin-bottom: 0;
    color: var(--gold-dim);
}

.cert-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px 24px;
}

.cert-grid dt {
    font-size: 0.76rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--text-dim);
    margin-bottom: 6px;
}

.cert-grid dd {
    margin: 0;
    color: var(--text-main);
    font-size: 1.05rem;
}

#seal {
    position: absolute;
    right: 14px;
    bottom: 14px;
    width: 118px;
    height: 118px;
    border: 2px solid rgba(215, 194, 137, 0.44);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: rgba(215, 194, 137, 0.72);
    font-size: 0.72rem;
    letter-spacing: 0.12em;
    transform: rotate(-12deg) scale(0.9);
    opacity: 0.3;
}

#seal.stamped {
    animation: stamp 520ms ease-out both;
}

@keyframes stamp {
    0% {
        transform: rotate(-12deg) scale(1.85);
        opacity: 0;
    }
    50% {
        transform: rotate(-12deg) scale(0.85);
        opacity: 0.88;
    }
    100% {
        transform: rotate(-12deg) scale(1);
        opacity: 0.72;
    }
}

#issue-certificate {
    margin-top: 22px;
    border: 1px solid rgba(215, 194, 137, 0.38);
    background: rgba(9, 14, 27, 0.9);
    color: var(--gold);
    padding: 10px 16px;
    border-radius: 999px;
    font: inherit;
    letter-spacing: 0.04em;
    cursor: pointer;
    transition: background 200ms ease, transform 200ms ease;
}

#issue-certificate:hover {
    background: rgba(20, 28, 48, 0.92);
    transform: translateY(-1px);
}

#issue-certificate:active {
    transform: translateY(1px);
}

.pulse {
    position: fixed;
    width: 14px;
    height: 14px;
    border: 1px solid rgba(239, 243, 255, 0.35);
    border-radius: 50%;
    pointer-events: none;
    z-index: 2;
    transform: translate(-50%, -50%);
    animation: pulse-wave 1.7s ease-out forwards;
}

@keyframes pulse-wave {
    to {
        width: 240px;
        height: 240px;
        opacity: 0;
    }
}

.petal {
    position: fixed;
    width: 7px;
    height: 11px;
    background: rgba(255, 154, 203, 0.7);
    border-radius: 70% 30% 70% 30%;
    pointer-events: none;
    z-index: 2;
    filter: blur(0.2px);
    animation: petal-fall 1.8s linear forwards;
}

@keyframes petal-fall {
    to {
        transform: translate(var(--drift-x), var(--drift-y)) rotate(var(--rot));
        opacity: 0;
    }
}

@media (max-width: 768px) {
    #lang-switcher {
        top: 10px;
        right: 10px;
    }

    .scene {
        padding: 40px 20px;
    }

    .counter-placeholder {
        font-size: 16px;
    }

    .milestones span {
        min-width: 96px;
    }

    .cert-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    #seal {
        width: 92px;
        height: 92px;
        font-size: 0.62rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    .scene {
        opacity: 1;
        transform: none;
        transition: none;
    }

    #intro-overlay {
        transition: none;
    }

    #seal.stamped,
    .pulse,
    .petal {
        animation: none;
    }
}