:root {
    --ink: #101820;
    --ink-soft: #3a4553;
    --muted: #6b7785;
    --line: #dfe5ec;
    --surface: #f3f6f8;
    --surface-2: #ffffff;
    --accent: #0f8a7a;
    --accent-deep: #0b6b5e;
    --accent-soft: #d8f3ee;
    --danger: #c62828;
    --warn: #c45c16;
    --radius: 12px;
    --nav-h: 68px;
    --shadow: 0 12px 40px rgba(16, 24, 32, 0.08);
    /* 使用系统字体，避免 Google Fonts 在国内阻塞首屏 */
    --font-display: 'Segoe UI Variable Display', 'Segoe UI', 'PingFang SC', 'HarmonyOS Sans SC', 'Microsoft YaHei UI', 'Microsoft YaHei', sans-serif;
    --font-body: 'Segoe UI', 'PingFang SC', 'HarmonyOS Sans SC', 'Microsoft YaHei UI', 'Microsoft YaHei', sans-serif;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px; /* 固定根字号，避免不同浏览器默认值导致 rem 整体缩放 */
}

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.65;
    color: var(--ink);
    background: var(--surface);
    -webkit-font-smoothing: antialiased;
    min-width: 320px;
}

img {
    max-width: 100%;
    display: block;
}

a {
    color: inherit;
}

button,
input {
    font: inherit;
}

/* 兼容写法：避免 min() 在部分环境下表现异常 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    box-sizing: border-box;
}

/* ---------- Nav ---------- */
.navbar {
    position: fixed;
    inset: 0 0 auto;
    z-index: 1000;
    height: var(--nav-h);
    background: rgba(243, 246, 248, 0.82);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid transparent;
    transition: background 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.navbar.is-scrolled {
    background: rgba(255, 255, 255, 0.92);
    border-bottom-color: var(--line);
    box-shadow: 0 4px 24px rgba(16, 24, 32, 0.04);
}

.navbar .container {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--ink);
}

.logo-mark {
    width: 34px;
    height: 34px;
    border-radius: 10px;
    background: linear-gradient(145deg, var(--accent) 0%, #147a9e 100%);
    color: #fff;
    display: grid;
    place-items: center;
    font-size: 15px;
}

.logo-text {
    font-family: var(--font-display);
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: -0.03em;
}

.brand-hero,
.logo-text,
.section-head h2,
.plan-header h3,
.plan-price .price,
.subscribe-header h2,
.login-card h2,
.cta-banner h2,
.feature-group-title {
    font-feature-settings: 'kern' 1;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 28px;
}

.nav-links a {
    text-decoration: none;
    color: var(--ink-soft);
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav-links a:hover,
.nav-links a.is-active {
    color: var(--accent);
}

.nav-links a.nav-auth-logout {
    color: var(--warn);
}

.nav-buttons {
    display: flex;
    align-items: center;
    gap: 12px;
}

.download-btn.navbar-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    border: none;
    border-radius: 10px;
    padding: 10px 16px;
    background: var(--ink);
    color: #fff;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: background 0.2s ease, transform 0.15s ease;
}

.download-btn.navbar-btn:hover {
    background: var(--accent-deep);
}

.download-btn.navbar-btn:active {
    transform: scale(0.97);
}

.download-btn:disabled {
    opacity: 0.65;
    cursor: not-allowed;
}

/* ---------- Hero ---------- */
.hero {
    position: relative;
    min-height: calc(100vh - var(--nav-h));
    margin-top: var(--nav-h);
    display: flex;
    align-items: center;
    overflow: hidden;
    color: #f4f7f8;
    background:
        radial-gradient(ellipse 80% 60% at 85% 20%, rgba(15, 138, 122, 0.35), transparent 55%),
        radial-gradient(ellipse 60% 50% at 10% 80%, rgba(20, 122, 158, 0.28), transparent 50%),
        linear-gradient(160deg, #0c141c 0%, #132029 45%, #0f1a22 100%);
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
    background-size: 48px 48px;
    mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 20%, transparent 75%);
    pointer-events: none;
}

.hero .container {
    position: relative;
    z-index: 1;
    padding: 72px 0 88px;
    max-width: 760px;
}

.brand-hero {
    font-family: var(--font-display);
    font-size: clamp(3.2rem, 8vw, 5.5rem);
    font-weight: 800;
    letter-spacing: -0.05em;
    line-height: 0.95;
    margin-bottom: 18px;
    background: linear-gradient(120deg, #ffffff 20%, #9fe8dc 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    animation: rise-in 0.7s ease both;
}

.hero h1 {
    font-family: var(--font-display);
    font-size: clamp(1.6rem, 3.2vw, 2.15rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.3;
    margin-bottom: 16px;
    color: #e8eef2;
    animation: rise-in 0.7s ease 0.08s both;
}

.hero-subtitle {
    font-size: 1.05rem;
    line-height: 1.8;
    color: rgba(232, 238, 242, 0.78);
    max-width: 540px;
    margin-bottom: 32px;
    animation: rise-in 0.7s ease 0.16s both;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    animation: rise-in 0.7s ease 0.24s both;
}

.hero-note {
    margin-top: 20px;
    font-size: 0.82rem;
    color: rgba(232, 238, 242, 0.5);
    animation: rise-in 0.7s ease 0.3s both;
}

@keyframes rise-in {
    from {
        opacity: 0;
        transform: translateY(18px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 22px;
    border-radius: 10px;
    border: none;
    font-weight: 600;
    font-size: 0.95rem;
    text-decoration: none;
    cursor: pointer;
    transition: transform 0.15s ease, background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn:active {
    transform: scale(0.97);
}

.btn-primary {
    background: #fff;
    color: var(--ink);
}

.btn-primary:hover {
    background: var(--accent-soft);
}

.btn-ghost {
    background: transparent;
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.35);
}

.btn-ghost:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.55);
}

/* ---------- Sections ---------- */
.section {
    padding: 88px 0;
}

.section-head {
    margin-bottom: 48px;
    max-width: 560px;
}

.section-head--center {
    text-align: center;
    margin-left: auto;
    margin-right: auto;
}

.section-eyebrow {
    display: inline-block;
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 10px;
}

.section-head h2 {
    font-family: var(--font-display);
    font-size: clamp(1.75rem, 3vw, 2.35rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.2;
    margin-bottom: 12px;
}

.section-head p {
    color: var(--muted);
    font-size: 1.02rem;
}

.section--white {
    background: var(--surface-2);
}

.section--muted {
    background: var(--surface);
}

/* ---------- Feature groups (list, not cards) ---------- */
.feature-group {
    padding: 36px 0;
    border-top: 1px solid var(--line);
}

.feature-group:first-of-type {
    border-top: none;
    padding-top: 0;
}

.feature-group-title {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 22px;
    color: var(--ink);
    display: flex;
    align-items: center;
    gap: 10px;
}

.feature-group-title span {
    display: inline-flex;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent);
}

.feature-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px 40px;
}

.feature-item {
    padding: 18px 0;
    border-bottom: 1px solid var(--line);
}

.feature-item h3 {
    font-size: 1.02rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--ink);
}

.feature-item p {
    font-size: 0.92rem;
    color: var(--muted);
    line-height: 1.65;
}

.reveal {
    opacity: 0;
    transform: translateY(22px);
    transition: opacity 0.55s ease, transform 0.55s ease;
}

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

/* ---------- Guide ---------- */
.guide-steps {
    display: grid;
    gap: 0;
    max-width: 720px;
}

.guide-step {
    display: grid;
    grid-template-columns: 56px 1fr;
    gap: 20px;
    padding: 28px 0;
    border-bottom: 1px solid var(--line);
}

.guide-step:last-child {
    border-bottom: none;
}

.step-number {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    background: var(--accent-soft);
    color: var(--accent-deep);
    display: grid;
    place-items: center;
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 1.15rem;
}

.step-content h3 {
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.step-content p {
    color: var(--muted);
    font-size: 0.95rem;
}

/* ---------- CTA ---------- */
.cta-banner {
    position: relative;
    padding: 80px 0;
    color: #f4f7f8;
    text-align: center;
    overflow: hidden;
    background:
        radial-gradient(ellipse 70% 80% at 50% 120%, rgba(15, 138, 122, 0.4), transparent 55%),
        linear-gradient(160deg, #0c141c 0%, #152530 100%);
}

.cta-banner h2 {
    font-family: var(--font-display);
    font-size: clamp(1.6rem, 3vw, 2.1rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 10px;
}

.cta-banner p {
    color: rgba(232, 238, 242, 0.72);
    margin-bottom: 28px;
}

.cta-banner .hero-buttons {
    justify-content: center;
}

/* ---------- Subscribe ---------- */
.subscribe-hero {
    margin-top: var(--nav-h);
    padding: 72px 0 48px;
    color: #f4f7f8;
    background:
        radial-gradient(ellipse 70% 60% at 80% 0%, rgba(15, 138, 122, 0.3), transparent 50%),
        linear-gradient(160deg, #0c141c 0%, #132029 100%);
}

.subscribe-hero .container {
    max-width: 720px;
}

.subscribe-hero .brand-hero {
    font-size: clamp(2.4rem, 5vw, 3.4rem);
    margin-bottom: 12px;
}

.subscribe-hero h1 {
    font-family: var(--font-display);
    font-size: clamp(1.35rem, 2.5vw, 1.75rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.35;
    margin-bottom: 14px;
    color: #e8eef2;
}

.subscribe-hero-desc {
    color: rgba(232, 238, 242, 0.72);
    font-size: 1rem;
    line-height: 1.75;
    max-width: 560px;
}

/* ---------- Versions ---------- */
.versions-hero {
    margin-top: var(--nav-h);
    padding: 72px 0 48px;
    color: #f4f7f8;
    background:
        radial-gradient(ellipse 70% 60% at 20% 10%, rgba(15, 138, 122, 0.28), transparent 52%),
        linear-gradient(160deg, #0c141c 0%, #132029 100%);
}

.versions-hero .container {
    max-width: 720px;
}

.versions-hero .brand-hero {
    font-size: clamp(2.4rem, 5vw, 3.4rem);
    margin-bottom: 12px;
}

.versions-hero h1 {
    font-family: var(--font-display);
    font-size: clamp(1.35rem, 2.5vw, 1.75rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.35;
    margin-bottom: 14px;
    color: #e8eef2;
}

.versions-hero-desc {
    color: rgba(232, 238, 242, 0.72);
    font-size: 1rem;
    line-height: 1.75;
    max-width: 560px;
}

.versions-section {
    padding: 48px 0 96px;
}

.versions-toolbar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 28px;
}

.versions-latest {
    margin: 0;
    color: var(--ink-soft);
    font-size: 0.95rem;
}

.versions-download-btn {
    min-width: 160px;
}

.versions-status {
    margin: 0 0 20px;
    color: var(--accent-deep);
    font-size: 0.92rem;
}

.versions-status--error {
    color: var(--danger);
}

.versions-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
    max-width: 720px;
}

.version-card {
    background: var(--surface-2);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 22px 24px;
}

.version-card--latest {
    border-color: rgba(15, 138, 122, 0.45);
    box-shadow: 0 0 0 1px rgba(15, 138, 122, 0.08);
}

.version-card-head {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    justify-content: space-between;
    gap: 8px 16px;
    margin-bottom: 14px;
}

.version-card-title {
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.version-card-title h2 {
    margin: 0;
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.version-badge {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 999px;
    background: var(--accent-soft);
    color: var(--accent-deep);
    font-size: 0.75rem;
    font-weight: 600;
}

.version-card-head time {
    color: var(--muted);
    font-size: 0.88rem;
}

.version-notes {
    margin: 0;
    padding-left: 1.15em;
    color: var(--ink-soft);
    font-size: 0.95rem;
    line-height: 1.7;
}

.version-notes li + li {
    margin-top: 6px;
}

.version-notes-empty {
    margin: 0;
    color: var(--muted);
    font-size: 0.92rem;
}

.subscribe-section {
    padding: 56px 0 96px;
}

.subscribe-feature-bullets {
    margin-bottom: 56px;
    padding-bottom: 48px;
    border-bottom: 1px solid var(--line);
}

.subscribe-feature-bullets h2 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.feature-bullet-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px 32px;
}

.feature-bullet-list li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-size: 0.95rem;
    color: var(--ink-soft);
    line-height: 1.55;
}

.feature-bullet-list li i {
    color: var(--accent);
    margin-top: 4px;
    flex-shrink: 0;
}

.subscribe-header {
    text-align: center;
    margin-bottom: 36px;
}

.subscribe-header h2 {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.subscribe-header p {
    color: var(--muted);
}

.subscription-plans {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 360px));
    justify-content: center;
    gap: 24px;
    margin-bottom: 64px;
}

.plan-card {
    position: relative;
    background: var(--surface-2);
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 32px 28px;
    text-align: center;
    transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.plan-card:hover {
    border-color: #b8cdc8;
    box-shadow: var(--shadow);
    transform: translateY(-3px);
}

.plan-card.yearly-plan {
    border-color: var(--accent);
    background: linear-gradient(180deg, #f4fbfa 0%, #fff 40%);
}

.plan-badge {
    position: absolute;
    top: -11px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent);
    color: #fff;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 4px 12px;
    border-radius: 999px;
}

.plan-header h3 {
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.plan-price {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 4px;
    margin-bottom: 24px;
}

.plan-price .price {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 800;
    letter-spacing: -0.04em;
    color: var(--ink);
    line-height: 1;
}

.yearly-plan .plan-price .price {
    color: var(--accent-deep);
}

.plan-price .unit {
    color: var(--muted);
    font-size: 0.95rem;
}

.plan-features {
    margin-bottom: 24px;
}

.plan-feature-list {
    list-style: none;
    text-align: left;
}

.plan-feature-list li {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
    color: var(--ink-soft);
    font-size: 0.92rem;
}

.plan-feature-list li i {
    color: var(--accent);
}

.subscribe-btn {
    width: 100%;
    border: none;
    border-radius: 10px;
    padding: 14px 20px;
    background: var(--ink);
    color: #fff;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s ease, transform 0.15s ease;
}

.subscribe-btn:hover {
    background: var(--accent-deep);
}

.subscribe-btn:active {
    transform: scale(0.98);
}

.yearly-plan .subscribe-btn {
    background: var(--accent);
}

.yearly-plan .subscribe-btn:hover {
    background: var(--accent-deep);
}

.subscribe-btn:disabled {
    background: #b0b8c0;
    cursor: not-allowed;
    transform: none;
}

.subscribe-status {
    color: var(--accent-deep);
    font-size: 0.88rem;
    line-height: 1.5;
    margin: 0 0 14px;
    min-height: 1.3em;
}

.subscribe-status--error {
    color: var(--danger);
}

.subscribe-disclaimer {
    text-align: center;
    color: var(--muted);
    font-size: 0.82rem;
    line-height: 1.7;
    max-width: 560px;
    margin: 0 auto;
}

/* ---------- 微信扫码支付弹层 ---------- */
.pay-qr-modal {
    position: fixed;
    inset: 0;
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    background: rgba(18, 24, 32, 0.55);
}

.pay-qr-modal[hidden] {
    display: none !important;
}

.pay-qr-dialog {
    position: relative;
    width: min(360px, 100%);
    background: #fff;
    border-radius: 16px;
    padding: 28px 24px 24px;
    text-align: center;
    box-shadow: 0 18px 48px rgba(0, 0, 0, 0.18);
}

.pay-qr-close {
    position: absolute;
    top: 10px;
    right: 12px;
    border: none;
    background: transparent;
    font-size: 1.6rem;
    line-height: 1;
    color: #889;
    cursor: pointer;
}

.pay-qr-dialog h3 {
    margin: 0 0 8px;
    font-size: 1.15rem;
    color: var(--ink);
}

.pay-qr-amount {
    margin: 0 0 16px;
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--accent-deep);
}

.pay-qr-box {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 236px;
    height: 236px;
    margin: 0 auto 14px;
    padding: 8px;
    border: 1px solid #e6eaf0;
    border-radius: 12px;
    background: #fff;
}

.pay-qr-box img,
.pay-qr-box canvas {
    display: block;
    max-width: 100%;
    height: auto;
}

.pay-qr-hint {
    margin: 0;
    font-size: 0.88rem;
    line-height: 1.55;
    color: var(--ink-soft);
}

/* ---------- Login ---------- */
.login-section {
    min-height: calc(100vh - var(--nav-h));
    margin-top: var(--nav-h);
    padding: 64px 0;
    display: flex;
    align-items: center;
    background:
        radial-gradient(ellipse 50% 40% at 90% 10%, rgba(15, 138, 122, 0.12), transparent 50%),
        var(--surface);
}

.login-card {
    width: 100%;
    max-width: 420px;
    margin: 0 auto;
    background: var(--surface-2);
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 36px 32px;
    box-shadow: var(--shadow);
}

.login-card h2 {
    font-family: var(--font-display);
    font-size: 1.6rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 28px;
}

.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--ink-soft);
    font-size: 0.9rem;
    font-weight: 500;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper i {
    position: absolute;
    left: 14px;
    color: var(--muted);
    font-size: 0.9rem;
    pointer-events: none;
}

.input-wrapper input {
    width: 100%;
    padding: 12px 14px 12px 40px;
    border: 1px solid var(--line);
    border-radius: 10px;
    background: #fff;
    color: var(--ink);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.input-wrapper input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(15, 138, 122, 0.15);
}

.verification-code {
    display: flex;
    gap: 10px;
    align-items: stretch;
}

.verification-code .input-wrapper {
    flex: 1;
}

.send-code-btn {
    border: 1px solid var(--line);
    background: var(--surface);
    color: var(--ink);
    padding: 0 14px;
    border-radius: 10px;
    font-size: 0.88rem;
    font-weight: 600;
    cursor: pointer;
    white-space: nowrap;
    transition: background 0.2s ease, border-color 0.2s ease;
}

.send-code-btn:hover:not(:disabled) {
    background: var(--accent-soft);
    border-color: #b7ddd6;
}

.send-code-btn:disabled {
    opacity: 0.55;
    cursor: not-allowed;
}

.login-btn {
    width: 100%;
    margin-top: 8px;
    border: none;
    border-radius: 10px;
    padding: 14px;
    background: var(--ink);
    color: #fff;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s ease;
}

.login-btn:hover:not(:disabled) {
    background: var(--accent-deep);
}

.login-btn:disabled {
    background: #b0b8c0;
    cursor: not-allowed;
}

.login-error {
    color: var(--danger);
    font-size: 0.88rem;
    margin-bottom: 12px;
}

/* ---------- Footer & utilities ---------- */
.footer {
    background: var(--ink);
    color: rgba(255, 255, 255, 0.65);
    padding: 28px 0;
}

.footer-bottom {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px 24px;
    text-align: center;
    font-size: 0.85rem;
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.75);
    text-decoration: none;
}

.footer-bottom a:hover {
    color: #fff;
}

.back-to-top {
    position: fixed;
    right: 24px;
    bottom: 24px;
    width: 44px;
    height: 44px;
    border: none;
    border-radius: 12px;
    background: var(--ink);
    color: #fff;
    font-size: 1rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(8px);
    transition: opacity 0.25s ease, visibility 0.25s ease, transform 0.25s ease, background 0.2s ease;
    z-index: 900;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--accent);
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
    .nav-links {
        display: none;
    }

    .feature-list,
    .feature-bullet-list {
        grid-template-columns: 1fr;
    }

    .subscription-plans {
        grid-template-columns: 1fr;
        max-width: 380px;
        margin-left: auto;
        margin-right: auto;
    }

    .plan-card.yearly-plan {
        transform: none;
    }
}

@media (max-width: 560px) {
    .container {
        padding: 0 16px;
    }

    .hero .container,
    .subscribe-hero {
        padding-top: 56px;
        padding-bottom: 64px;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .btn {
        width: 100%;
    }

    .guide-step {
        grid-template-columns: 40px 1fr;
        gap: 14px;
    }

    .step-number {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }

    .login-card {
        padding: 28px 20px;
    }
}