:root {
    --ink: #0f1c24;
    --ink-soft: #243640;
    --paper: #f7f4ef;
    --paper-deep: #ebe4d8;
    --sand: #d8cfc0;
    --accent: #b8862d;
    --accent-deep: #8f671f;
    --accent-glow: rgba(184, 134, 45, 0.22);
    --danger: #9b2c2c;
    --danger-soft: #f3e4e0;
    --line: rgba(15, 28, 36, 0.12);
    --text: #1d2a32;
    --text-muted: #5a6a74;
    --white: #fffdf9;
    --shadow: 0 24px 60px rgba(15, 28, 36, 0.12);
    --font-display: "Noto Serif SC", "Songti SC", "STSong", serif;
    --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
    --max: 760px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    color: var(--text);
    background:
        radial-gradient(900px 480px at 12% -8%, rgba(184, 134, 45, 0.14), transparent 55%),
        radial-gradient(700px 420px at 100% 8%, rgba(36, 54, 64, 0.1), transparent 50%),
        linear-gradient(180deg, #f3efe7 0%, var(--paper) 38%, #f0ebe3 100%);
    line-height: 1.75;
    -webkit-font-smoothing: antialiased;
    min-height: 100vh;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    opacity: 0.035;
    background-image:
        linear-gradient(30deg, #0f1c24 1px, transparent 1px),
        linear-gradient(150deg, #0f1c24 1px, transparent 1px);
    background-size: 28px 28px;
    z-index: 0;
}

a {
    color: inherit;
    text-decoration: none;
}

.page {
    position: relative;
    z-index: 1;
}

/* ========== Hero ========== */
.hero {
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    overflow: hidden;
    color: var(--white);
    background:
        linear-gradient(165deg, rgba(15, 28, 36, 0.2) 0%, rgba(15, 28, 36, 0.72) 55%, rgba(15, 28, 36, 0.92) 100%),
        radial-gradient(1200px 700px at 70% 20%, rgba(184, 134, 45, 0.28), transparent 55%),
        linear-gradient(135deg, #1a303b 0%, #0f1c24 48%, #15262f 100%);
}

.hero-visual {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 18% 72%, rgba(184, 134, 45, 0.18), transparent 28%),
        radial-gradient(circle at 82% 30%, rgba(255, 253, 249, 0.06), transparent 24%);
    pointer-events: none;
}

.hero-visual::after {
    content: "";
    position: absolute;
    right: -8%;
    bottom: -18%;
    width: min(72vw, 560px);
    height: min(72vw, 560px);
    border-radius: 50%;
    border: 1px solid rgba(255, 253, 249, 0.08);
    box-shadow:
        inset 0 0 0 40px rgba(255, 253, 249, 0.02),
        inset 0 0 0 80px rgba(184, 134, 45, 0.04);
    animation: ring-drift 14s ease-in-out infinite alternate;
}

.hero-inner {
    position: relative;
    width: min(100% - 40px, 920px);
    margin: 0 auto;
    padding: 36px 0 40px;
}

.brand {
    display: inline-flex;
    align-items: stretch;
    gap: 14px;
    margin-bottom: 16px;
    opacity: 0;
    transform: translateY(18px);
    animation: rise-in 0.9s cubic-bezier(0.22, 1, 0.36, 1) 0.1s forwards;
}

.brand-mark {
    font-family: var(--font-display);
    font-size: clamp(2.1rem, 5.5vw, 3.2rem);
    font-weight: 700;
    letter-spacing: 0.12em;
    line-height: 1;
    color: var(--white);
    text-shadow: 0 10px 40px rgba(0, 0, 0, 0.35);
}

.brand-sub {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
    align-self: stretch;
    padding: 2px 0;
    font-size: 0.78rem;
    font-weight: 500;
    letter-spacing: 0.2em;
    line-height: 1.15;
    color: rgba(255, 253, 249, 0.62);
    writing-mode: horizontal-tb;
    white-space: nowrap;
}

.brand-sub span {
    display: block;
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(1.55rem, 3.8vw, 2.35rem);
    font-weight: 700;
    letter-spacing: 0.08em;
    line-height: 1.25;
    margin-bottom: 12px;
    max-width: 14em;
    opacity: 0;
    transform: translateY(22px);
    animation: rise-in 0.95s cubic-bezier(0.22, 1, 0.36, 1) 0.28s forwards;
}

.hero-lead {
    font-size: clamp(0.95rem, 1.8vw, 1.05rem);
    color: rgba(255, 253, 249, 0.78);
    max-width: 28em;
    margin-bottom: 22px;
    opacity: 0;
    transform: translateY(22px);
    animation: rise-in 0.95s cubic-bezier(0.22, 1, 0.36, 1) 0.42s forwards;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    opacity: 0;
    transform: translateY(22px);
    animation: rise-in 0.95s cubic-bezier(0.22, 1, 0.36, 1) 0.56s forwards;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 46px;
    padding: 0 22px;
    border-radius: 999px;
    font-size: 0.92rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    border: 1px solid transparent;
    transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.btn-primary {
    background: linear-gradient(135deg, #d4a84b 0%, var(--accent) 55%, var(--accent-deep) 100%);
    color: #1a1408;
    box-shadow: 0 10px 28px rgba(184, 134, 45, 0.28);
}

.btn-primary:hover {
    transform: translateY(-1px);
}

.btn-ghost {
    border-color: rgba(255, 253, 249, 0.28);
    color: rgba(255, 253, 249, 0.9);
    background: rgba(255, 253, 249, 0.04);
}

.btn-ghost:hover {
    border-color: rgba(255, 253, 249, 0.5);
    background: rgba(255, 253, 249, 0.08);
}

.hero-meta {
    margin-top: 24px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px 22px;
    font-size: 0.8rem;
    letter-spacing: 0.06em;
    color: rgba(255, 253, 249, 0.48);
    opacity: 0;
    animation: rise-in 0.9s cubic-bezier(0.22, 1, 0.36, 1) 0.7s forwards;
}

.scroll-hint {
    display: none;
}

/* ========== Letter body ========== */
.letter-shell {
    width: min(100% - 28px, 860px);
    margin: -28px auto 64px;
    position: relative;
}

.letter {
    background:
        linear-gradient(180deg, rgba(255, 253, 249, 0.97), rgba(247, 244, 239, 0.98)),
        var(--white);
    border: 1px solid rgba(15, 28, 36, 0.08);
    box-shadow: var(--shadow);
    padding: clamp(28px, 5vw, 56px) clamp(20px, 5vw, 64px) clamp(36px, 5vw, 64px);
    position: relative;
    overflow: hidden;
}

.letter::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(180deg, var(--accent), var(--accent-deep));
}

.letter-seal {
    position: absolute;
    right: clamp(16px, 4vw, 40px);
    top: clamp(16px, 4vw, 36px);
    width: 88px;
    height: 88px;
    border: 2px solid rgba(155, 44, 44, 0.55);
    border-radius: 50%;
    color: rgba(155, 44, 44, 0.72);
    display: grid;
    place-items: center;
    text-align: center;
    font-family: var(--font-display);
    font-size: 0.78rem;
    letter-spacing: 0.18em;
    line-height: 1.35;
    transform: rotate(-12deg);
    background: rgba(243, 228, 224, 0.35);
    pointer-events: none;
    animation: seal-in 1.1s cubic-bezier(0.22, 1, 0.36, 1) 0.8s both;
}

.salute {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 18px;
    color: var(--ink);
}

.prose p {
    margin-bottom: 1.05em;
    font-size: 1rem;
    text-align: justify;
    text-justify: inter-ideograph;
}

.prose p:last-child {
    margin-bottom: 0;
}

.emphasis {
    color: var(--danger);
    font-weight: 600;
}

.bridge {
    margin: 28px 0 8px;
    padding: 16px 18px;
    border-left: 3px solid var(--accent);
    background: linear-gradient(90deg, rgba(184, 134, 45, 0.1), transparent 85%);
    color: var(--ink-soft);
    font-size: 0.98rem;
}

/* ========== Sections ========== */
.section {
    margin-top: 42px;
    padding-top: 8px;
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.8s cubic-bezier(0.22, 1, 0.36, 1), transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}

.section.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.section-head {
    display: flex;
    align-items: baseline;
    gap: 12px;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--line);
}

.section-index {
    font-family: var(--font-display);
    font-size: 0.85rem;
    letter-spacing: 0.16em;
    color: var(--accent-deep);
    white-space: nowrap;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(1.2rem, 2.6vw, 1.45rem);
    font-weight: 700;
    color: var(--ink);
    letter-spacing: 0.04em;
}

.item {
    margin-top: 22px;
}

.item-title {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-weight: 700;
    color: var(--ink);
    margin-bottom: 8px;
    font-size: 1.02rem;
}

.item-num {
    flex: 0 0 auto;
    min-width: 1.6em;
    color: var(--accent-deep);
    font-family: var(--font-display);
}

.item p {
    color: var(--text);
    padding-left: 0;
}

.item + .item {
    padding-top: 4px;
}

.harm-list .item-title {
    color: var(--danger);
}

.appeal-lead {
    margin-bottom: 16px;
}

.appeal-list {
    list-style: none;
    margin: 18px 0 22px;
    display: grid;
    gap: 10px;
}

.appeal-list li {
    position: relative;
    padding: 12px 14px 12px 42px;
    background: linear-gradient(90deg, rgba(155, 44, 44, 0.06), transparent 90%);
    border-left: 2px solid rgba(155, 44, 44, 0.35);
    font-size: 0.98rem;
}

.appeal-list li::before {
    content: "勿";
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--danger);
    color: #fff;
    font-size: 0.72rem;
    font-weight: 700;
    display: grid;
    place-items: center;
    letter-spacing: 0;
}

.closing {
    margin-top: 28px;
}

.closing .motto {
    font-family: var(--font-display);
    font-size: 1.12rem;
    font-weight: 700;
    color: var(--ink);
    letter-spacing: 0.06em;
    margin: 18px 0 10px;
}

.signoff {
    margin-top: 40px;
    text-align: right;
    font-family: var(--font-display);
}

.signoff .company {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--ink);
    letter-spacing: 0.04em;
}

.signoff .date {
    margin-top: 8px;
    color: var(--text-muted);
    letter-spacing: 0.12em;
}

.footer {
    width: min(100% - 28px, 860px);
    margin: 0 auto 48px;
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-muted);
    letter-spacing: 0.04em;
}

@keyframes rise-in {
    from {
        opacity: 0;
        transform: translateY(22px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes scroll-dot {
    0%, 100% { transform: translateY(0); opacity: 0.35; }
    45% { transform: translateY(12px); opacity: 1; }
}

@keyframes ring-drift {
    from { transform: translate(0, 0) scale(1); opacity: 0.7; }
    to { transform: translate(-24px, -18px) scale(1.04); opacity: 1; }
}

@keyframes seal-in {
    from {
        opacity: 0;
        transform: rotate(-12deg) scale(1.2);
    }
    to {
        opacity: 1;
        transform: rotate(-12deg) scale(1);
    }
}

@media (max-width: 640px) {
    .hero-inner {
        padding: 28px 0 32px;
    }

    .letter-seal {
        width: 70px;
        height: 70px;
        font-size: 0.66rem;
        letter-spacing: 0.12em;
    }

    .letter-shell {
        margin-top: -20px;
    }

    .appeal-list li {
        padding-left: 40px;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation: none !important;
        transition: none !important;
    }

    .brand,
    .hero-title,
    .hero-lead,
    .hero-actions,
    .hero-meta,
    .section {
        opacity: 1;
        transform: none;
    }
}