/* =================================================================
   Changelog Page — v3 Neo-Brutalism
   navy + orange + butter | Bricolage + Hanken + Fraunces + JetBrains
   共用 landing.css nav + mobile menu + footer v3
   本檔專注：hero、filter tabs、timeline、4 種 tag 色、CTA
   ================================================================= */

body.changelog-page {
    font-family: var(--brand-v3-sans);
    color: var(--brand-v3-ink-soft);
    background: var(--brand-v3-cream);
}

body.changelog-page em,
.changelog-page .italic {
    font-family: var(--brand-v3-serif);
    font-style: italic;
    font-weight: 500;
    color: var(--brand-v3-orange);
    font-variation-settings: "opsz" 144;
}

/* ========== Hero ========== */
.changelog-hero {
    position: relative;
    padding: 64px 24px 48px;
    text-align: center;
    overflow: hidden;
    background: var(--brand-v3-cream);
    border-bottom: 2.5px solid var(--brand-v3-navy);
}

.changelog-hero-bg-blob {
    position: absolute;
    border-radius: 50%;
    pointer-events: none;
    opacity: 0.45;
    z-index: 0;
}

.changelog-hero-bg-blob.orange {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--brand-v3-orange-soft) 0%, transparent 65%);
    top: -100px;
    right: -80px;
}

.changelog-hero-bg-blob.yellow {
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, var(--brand-v3-butter) 0%, transparent 65%);
    bottom: -60px;
    left: -40px;
}

.changelog-hero-inner {
    position: relative;
    z-index: 1;
    max-width: 720px;
    margin: 0 auto;
}

.changelog-hero-title {
    font-family: var(--brand-v3-display);
    font-size: clamp(32px, 5vw, 58px);
    font-weight: 800;
    color: var(--brand-v3-navy);
    margin: 0 0 16px;
    line-height: 1.03;
    letter-spacing: -0.035em;
    font-variation-settings: "opsz" 72, "wdth" 92;
}

.changelog-hero-subtitle {
    font-family: var(--brand-v3-sans);
    font-size: clamp(16px, 1.8vw, 18px);
    font-weight: 500;
    color: var(--brand-v3-ink-soft);
    margin: 0 auto;
    max-width: 580px;
    line-height: 1.6;
}

/* ========== Filter Tabs（v3 pill） ========== */
.changelog-filter {
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 28px 24px 8px;
    margin-bottom: 32px;
    flex-wrap: wrap;
}

.changelog-filter-btn {
    font-family: var(--brand-v3-mono);
    font-size: 11.5px;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    padding: 8px 16px;
    border-radius: 999px;
    border: 2px solid var(--brand-v3-navy);
    background: var(--brand-v3-paper);
    color: var(--brand-v3-navy);
    cursor: pointer;
    white-space: nowrap;
    box-shadow: var(--brand-v3-shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.changelog-filter-btn:hover {
    background: var(--brand-v3-butter);
    transform: translate(-1px, -1px);
    box-shadow: var(--brand-v3-shadow-md);
}

.changelog-filter-btn.active {
    background: var(--brand-v3-navy);
    color: var(--brand-v3-cream);
    box-shadow: var(--brand-v3-shadow-primary-md);
}

.changelog-filter-btn.active:hover {
    background: var(--brand-v3-navy-2);
    box-shadow: var(--brand-v3-shadow-primary-lg);
}

/* ========== Timeline ========== */
.changelog-timeline {
    max-width: 780px;
    margin: 0 auto;
    padding: 8px 24px 64px 24px;
    position: relative;
}

/* 左側時間軸線（dashed navy） */
.changelog-timeline::before {
    content: '';
    position: absolute;
    left: calc(24px + 10px);    /* padding-left + 圓點半徑 */
    top: 18px;
    bottom: 20px;
    width: 2.5px;
    background: repeating-linear-gradient(
        to bottom,
        var(--brand-v3-navy) 0 8px,
        transparent 8px 14px
    );
    opacity: 0.5;
    z-index: 0;
}

/* ========== Timeline Entry ========== */
.changelog-entry {
    position: relative;
    padding: 22px 24px 22px 48px;
    margin-bottom: 18px;
    background: var(--brand-v3-paper);
    border: 2.5px solid var(--brand-v3-navy);
    border-radius: 16px;
    box-shadow: var(--brand-v3-shadow-md);
    transition: transform 0.3s cubic-bezier(.2,.8,.2,1), box-shadow 0.3s ease;
}

.changelog-entry:hover {
    transform: translate(-2px, -2px);
    box-shadow: var(--brand-v3-shadow-lg);
}

/* 左側小圓點（tag 色 + navy 邊） */
.changelog-entry::before {
    content: '';
    position: absolute;
    left: -16px;                /* 突出 card 外 */
    top: 26px;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--brand-v3-butter);
    border: 2.5px solid var(--brand-v3-navy);
    box-shadow: var(--brand-v3-shadow-sm);
    z-index: 2;
}

/* 4 種 tag 圓點填充色 */
.changelog-entry[data-tag="launch"]::before {
    background: var(--brand-v3-navy);
}

.changelog-entry[data-tag="new"]::before {
    background: var(--brand-v3-orange);
}

.changelog-entry[data-tag="improve"]::before {
    background: var(--brand-v3-orange-soft);
}

.changelog-entry[data-tag="fix"]::before {
    background: var(--brand-v3-cream-2);
}

/* Entry Header（tag + version + date） */
.changelog-entry-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
    flex-wrap: wrap;
}

/* Tag pill（各色變體） */
.changelog-tag {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 999px;
    font-family: var(--brand-v3-mono);
    font-size: 10.5px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.14em;
    border: 2px solid var(--brand-v3-navy);
    box-shadow: var(--brand-v3-shadow-sm);
    background: var(--brand-v3-butter);
    color: var(--brand-v3-navy);
}

.changelog-tag[data-tag="launch"] {
    background: var(--brand-v3-navy);
    color: var(--brand-v3-cream);
}

.changelog-tag[data-tag="new"] {
    background: var(--brand-v3-orange);
    color: var(--brand-v3-paper);
}

.changelog-tag[data-tag="improve"] {
    background: var(--brand-v3-orange-soft);
    color: var(--brand-v3-navy);
}

.changelog-tag[data-tag="fix"] {
    background: var(--brand-v3-cream-2);
    color: var(--brand-v3-navy);
}

.changelog-version {
    font-family: var(--brand-v3-mono);
    font-size: 12.5px;
    font-weight: 700;
    color: var(--brand-v3-navy);
    letter-spacing: 0.04em;
}

.changelog-date {
    font-family: var(--brand-v3-mono);
    font-size: 11.5px;
    font-weight: 600;
    color: var(--brand-v3-muted);
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.changelog-entry-title {
    font-family: var(--brand-v3-display);
    font-size: 19px;
    font-weight: 800;
    color: var(--brand-v3-navy);
    margin: 0 0 10px;
    line-height: 1.25;
    letter-spacing: -0.015em;
}

.changelog-entry-items {
    list-style: none;
    padding: 0;
    margin: 0;
}

.changelog-entry-items li {
    position: relative;
    padding: 5px 0 5px 20px;
    font-family: var(--brand-v3-sans);
    font-size: 14.5px;
    line-height: 1.65;
    color: var(--brand-v3-ink-soft);
}

.changelog-entry-items li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 12px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--brand-v3-orange);
    border: 1.5px solid var(--brand-v3-navy);
}

/* ========== Empty State ========== */
.changelog-empty {
    text-align: center;
    padding: 72px 24px;
    max-width: 480px;
    margin: 0 auto;
}

.changelog-empty-icon {
    width: 60px;
    height: 60px;
    color: var(--brand-v3-navy);
    opacity: 0.35;
    margin-bottom: 20px;
}

.changelog-empty-title {
    font-family: var(--brand-v3-display);
    font-size: 24px;
    font-weight: 800;
    color: var(--brand-v3-navy);
    margin: 0 0 10px;
    letter-spacing: -0.02em;
}

.changelog-empty-desc {
    font-family: var(--brand-v3-sans);
    font-size: 15px;
    color: var(--brand-v3-ink-soft);
    line-height: 1.6;
}

/* ========== CTA（深 navy 底） ========== */
.changelog-cta {
    text-align: center;
    padding: 88px 24px;
    background: var(--brand-v3-navy);
    position: relative;
    overflow: hidden;
    border-top: 2.5px solid var(--brand-v3-navy);
}

.changelog-cta::before {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, var(--brand-v3-orange-deep) 0%, transparent 55%);
    opacity: 0.22;
    transform: translate(-50%, -50%);
    pointer-events: none;
}

.changelog-cta-inner {
    position: relative;
    z-index: 1;
    max-width: 580px;
    margin: 0 auto;
}

.changelog-cta-title {
    font-family: var(--brand-v3-display);
    font-size: clamp(26px, 3.6vw, 36px);
    font-weight: 800;
    color: var(--brand-v3-cream);
    margin: 0 0 14px;
    letter-spacing: -0.025em;
    line-height: 1.1;
}

.changelog-cta-subtitle {
    font-family: var(--brand-v3-sans);
    font-size: 15.5px;
    color: var(--brand-v3-cream);
    opacity: 0.82;
    margin: 0 0 30px;
    line-height: 1.6;
}

.changelog-cta-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 32px;
    background: var(--brand-v3-orange);
    color: var(--brand-v3-paper);
    border: 2.5px solid var(--brand-v3-paper);
    border-radius: 999px;
    font-family: var(--brand-v3-sans);
    font-size: 15px;
    font-weight: 700;
    text-decoration: none;
    box-shadow: 5px 5px 0 var(--brand-v3-orange-deep);
    transition: transform 0.25s cubic-bezier(.2,.8,.2,1), box-shadow 0.25s ease, background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
    letter-spacing: -0.005em;
}

.changelog-cta-btn:hover {
    background: var(--brand-v3-paper);
    color: var(--brand-v3-navy);
    border-color: var(--brand-v3-navy);
    transform: translate(-2px, -2px);
    box-shadow: 7px 7px 0 var(--brand-v3-cream);
}

/* =================================================================
   RWD 斷點系統（對齊 v3 skill §17）
   ≤820: padding 縮、hero 字縮、filter 字縮、timeline padding 縮
   ≤640: entry header 直排、tag/version/date 縮
   ================================================================= */

@media (max-width: 820px) {
    .changelog-hero {
        padding: 48px 20px 40px;
    }

    .changelog-hero-title {
        font-size: clamp(26px, 7vw, 40px);
    }

    .changelog-hero-subtitle {
        font-size: 15.5px;
    }

    .changelog-filter {
        padding: 22px 18px 4px;
        gap: 6px;
    }

    .changelog-filter-btn {
        font-size: 10.5px;
        padding: 6px 12px;
    }

    .changelog-timeline {
        padding: 8px 20px 52px 20px;
    }

    .changelog-timeline::before {
        left: calc(20px + 10px);
    }

    .changelog-entry {
        padding: 20px 20px 20px 40px;
    }

    .changelog-cta {
        padding: 64px 20px;
    }

    .changelog-hero-bg-blob.orange {
        width: 300px;
        height: 300px;
        opacity: 0.32;
    }

    .changelog-hero-bg-blob.yellow {
        width: 240px;
        height: 240px;
        opacity: 0.32;
    }
}

@media (max-width: 640px) {
    .changelog-hero {
        padding: 40px 18px 36px;
    }

    .changelog-hero-title {
        font-size: clamp(22px, 8vw, 32px);
        letter-spacing: -0.025em;
    }

    .changelog-entry-header {
        gap: 8px;
    }

    .changelog-tag {
        font-size: 10px;
        padding: 3px 10px;
    }

    .changelog-version,
    .changelog-date {
        font-size: 11px;
    }

    .changelog-entry-title {
        font-size: 17px;
    }

    .changelog-entry-items li {
        font-size: 14px;
    }

    .changelog-cta {
        padding: 52px 18px;
    }

    .changelog-cta-btn {
        padding: 13px 28px;
        font-size: 14px;
    }
}

/* =================================================================
   滾動進場動畫（v3 skill §18 — CSS 3 translate 不碰 transform）
   覆蓋 landing.css global .animate-on-scroll
   ================================================================= */
.changelog-entry.animate-on-scroll,
.changelog-cta-inner.animate-on-scroll {
    opacity: 0;
    transform: none;
    translate: 0 20px;
    transition: opacity 0.6s cubic-bezier(.2,.8,.2,1),
                translate 0.6s cubic-bezier(.2,.8,.2,1);
}

.changelog-entry.animate-on-scroll.visible,
.changelog-entry.animate-on-scroll.in-view,
.changelog-cta-inner.animate-on-scroll.visible,
.changelog-cta-inner.animate-on-scroll.in-view {
    opacity: 1;
    translate: 0 0;
}

/* 前 2 個 entry（第一眼可見）跳過動畫 */
.changelog-entry:nth-child(1).animate-on-scroll,
.changelog-entry:nth-child(2).animate-on-scroll {
    opacity: 1;
    translate: 0 0;
    transition: none;
}

/* ========== Reduced Motion ========== */
@media (prefers-reduced-motion: reduce) {
    .changelog-entry.animate-on-scroll,
    .changelog-cta-inner.animate-on-scroll {
        opacity: 1 !important;
        translate: 0 0 !important;
        transition: none !important;
    }

    .changelog-entry {
        transform: none !important;
    }
}