/* Corenk — App Support Website */
/* Pure HTML/CSS, lightweight & responsive */

:root {
    --color-bg: #ffffff;
    --color-surface: #f7f7f8;
    --color-border: #ececef;
    --color-text: #111114;
    --color-text-muted: #6b6b73;
    --color-accent: #111114;
    --color-accent-soft: #f1eaff;
    --color-green: #4cc26a;
    --color-purple: #b39bff;
    --color-pink: #ff7aa2;
    --radius-sm: 10px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --shadow-sm: 0 1px 2px rgba(17, 17, 20, 0.04);
    --shadow-md: 0 8px 24px rgba(17, 17, 20, 0.06);
    --max-width: 1080px;
    --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
    background: var(--color-bg);
    color: var(--color-text);
    font-family: var(--font);
    font-size: 16px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: var(--color-text);
    text-decoration: none;
    transition: opacity 0.15s ease;
}

a:hover {
    opacity: 0.65;
}

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

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- Header ---------- */
.site-header {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    border-bottom: 1px solid var(--color-border);
    z-index: 50;
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 18px;
    letter-spacing: -0.01em;
}

.brand img {
    width: 32px;
    height: 32px;
    object-fit: contain;
}

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

.nav-links a {
    font-size: 14px;
    color: var(--color-text-muted);
    font-weight: 500;
}

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

.lang-switch {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-left: 8px;
    padding-left: 18px;
    border-left: 1px solid var(--color-border);
}

.lang-switch a {
    font-size: 13px;
    font-weight: 600;
    color: var(--color-text-muted);
    letter-spacing: 0.02em;
}

.lang-switch a.active {
    color: var(--color-text);
}

.lang-sep {
    color: var(--color-border);
    font-size: 12px;
}

@media (max-width: 640px) {
    .nav-links {
        gap: 16px;
    }
    .nav-links a {
        font-size: 13px;
    }
    .lang-switch {
        margin-left: 0;
        padding-left: 12px;
    }
}

/* ---------- Hero ---------- */
.hero {
    padding: 80px 0 60px;
    text-align: center;
}

.hero h1 {
    font-size: clamp(36px, 6vw, 64px);
    line-height: 1.05;
    letter-spacing: -0.03em;
    margin: 0 0 18px;
    font-weight: 800;
}

.hero .tagline {
    font-size: clamp(16px, 2vw, 20px);
    color: var(--color-text-muted);
    max-width: 640px;
    margin: 0 auto 32px;
}

.hero-logo {
    width: 144px;
    height: 144px;
    margin: 0 auto 32px;
    display: block;
    object-fit: contain;
}

@media (max-width: 640px) {
    .hero-logo {
        width: 112px;
        height: 112px;
    }
}

.cta-row {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 8px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 22px;
    border-radius: 999px;
    font-weight: 600;
    font-size: 15px;
    border: 1px solid transparent;
    cursor: pointer;
}

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

.btn-primary:hover {
    opacity: 0.85;
}

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text);
    border-color: var(--color-border);
}

/* ---------- Screenshots ---------- */
.screens {
    padding: 40px 0 80px;
}

.screens-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    align-items: end;
}

.screens-grid img {
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
}

@media (max-width: 760px) {
    .screens-grid {
        grid-template-columns: 1fr;
        max-width: 320px;
        margin: 0 auto;
    }
}

/* ---------- Sections ---------- */
section {
    padding: 64px 0;
}

section h2 {
    font-size: clamp(26px, 3.5vw, 36px);
    letter-spacing: -0.02em;
    font-weight: 700;
    margin: 0 0 16px;
}

section p {
    color: var(--color-text-muted);
    max-width: 720px;
}

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

/* ---------- Features ---------- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 36px;
}

@media (max-width: 820px) {
    .features-grid {
        grid-template-columns: 1fr;
    }
}

.feature {
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 24px;
    box-shadow: var(--shadow-sm);
}

.feature h3 {
    font-size: 17px;
    margin: 0 0 8px;
    font-weight: 700;
}

.feature p {
    margin: 0;
    font-size: 14.5px;
    color: var(--color-text-muted);
}

.feature-icon {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    margin-bottom: 14px;
    background: var(--color-accent-soft);
}

/* ---------- Steps (How it works) ---------- */
.steps {
    position: relative;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 48px;
}

/* Horizontal connector line behind step circles (desktop only) */
.steps::before {
    content: "";
    position: absolute;
    top: 34px;
    left: 12.5%;
    right: 12.5%;
    height: 2px;
    background: linear-gradient(
        to right,
        var(--color-border) 0%,
        var(--color-border) 100%
    );
    z-index: 0;
}

@media (max-width: 820px) {
    .steps {
        grid-template-columns: 1fr 1fr;
    }
    .steps::before {
        display: none;
    }
}

@media (max-width: 480px) {
    .steps {
        grid-template-columns: 1fr;
    }
}

.step {
    position: relative;
    background: transparent;
    border: none;
    border-radius: 0;
    padding: 0;
    text-align: center;
    z-index: 1;
}

.step-circle {
    position: relative;
    width: 68px;
    height: 68px;
    margin: 0 auto 18px;
    border-radius: 50%;
    background: #fff;
    border: 2px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.step:hover .step-circle {
    transform: translateY(-3px);
    border-color: var(--color-text);
}

.step-num {
    position: absolute;
    top: -6px;
    right: -6px;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    background: var(--color-text);
    color: #fff;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 700;
    border: 2px solid #fff;
}

.step h4 {
    margin: 0 0 6px;
    font-size: 16px;
    font-weight: 700;
}

.step p {
    margin: 0 auto;
    font-size: 14px;
    color: var(--color-text-muted);
    max-width: 220px;
}

/* ---------- Store buttons (App Store / Google Play) ---------- */
.store-buttons {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 8px;
}

.store-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    border-radius: 14px;
    background: #111114;
    color: #fff;
    text-decoration: none;
    min-width: 180px;
    transition: transform 0.15s ease, opacity 0.15s ease;
}

.store-btn:hover {
    opacity: 1;
    transform: translateY(-2px);
}

.store-btn-icon {
    width: 26px;
    height: 26px;
    flex-shrink: 0;
    object-fit: contain;
}

.store-btn-text {
    display: flex;
    flex-direction: column;
    line-height: 1.1;
    text-align: left;
}

.store-btn-text small {
    font-size: 10px;
    font-weight: 500;
    opacity: 0.85;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.store-btn-text strong {
    font-size: 17px;
    font-weight: 600;
    letter-spacing: -0.01em;
}

.cta-secondary {
    margin-top: 18px;
    font-size: 14px;
    color: var(--color-text-muted);
    text-align: center;
}

.cta-secondary a {
    color: var(--color-text);
    text-decoration: underline;
    text-underline-offset: 3px;
    font-weight: 500;
}

/* ---------- Doc pages ---------- */
.doc {
    padding: 56px 0 80px;
}

.doc h1 {
    font-size: clamp(28px, 4vw, 40px);
    margin: 0 0 8px;
    letter-spacing: -0.02em;
}

.doc .updated {
    color: var(--color-text-muted);
    font-size: 14px;
    margin-bottom: 32px;
}

.doc h2 {
    font-size: 20px;
    margin: 32px 0 8px;
    letter-spacing: -0.01em;
}

.doc p,
.doc li {
    color: #2c2c33;
    font-size: 15.5px;
}

.doc ul {
    padding-left: 20px;
}

.doc a {
    color: var(--color-text);
    text-decoration: underline;
    text-underline-offset: 3px;
}

/* ---------- Footer ---------- */
.site-footer {
    border-top: 1px solid var(--color-border);
    padding: 32px 0;
    background: var(--color-bg);
}

.footer-row {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.footer-links {
    display: flex;
    gap: 22px;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--color-text-muted);
    font-size: 14px;
}

.copyright {
    color: var(--color-text-muted);
    font-size: 13px;
}