/* ==========================================================================
   I'm Okay — brand theme (matches imokay-flutter app theme)
   Brand primary: #10B981 (emerald-500)
   Light gradient: #34D399 → #10B981 → #059669
   Dark  gradient: #059669 → #047857 → #065F46
   Dark surfaces : bg #1F2937 / card #374151 (app dark_theme.dart)
   ========================================================================== */

/* ---- Theme tokens ---- */
:root {
    color-scheme: light;

    --brand: #10b981;
    --brand-light: #34d399;
    --brand-deep: #059669;

    --bg: #ffffff;
    --bg-alt: #f9fafb;
    --card: #f9fafb;
    --card-border: #e5e7eb;

    --heading: #1f2937;
    --text: #374151;
    --muted: #6b7280;

    --accent: #10b981;
    --accent-text: #047857;      /* text-level accent, AA on white */
    --accent-hover: #059669;

    --btn-primary-bg: #10b981;
    --btn-primary-hover: #059669;
    --btn-primary-text: #ffffff;

    --danger: #ef4444;

    --divider: #e5e7eb;
    --input-bg: #ffffff;
    --input-border: #d1d5db;

    --nav-bg: rgba(255, 255, 255, 0.92);
    --nav-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    --nav-shadow-scrolled: 0 4px 20px rgba(0, 0, 0, 0.12);

    --hero-bg: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
    --brand-gradient: linear-gradient(160deg, #34d399 0%, #10b981 45%, #059669 100%);

    --screen-bg: #ffffff;
    --download-card-bg: #ffffff;
    --notice-bg: #f0fdf4;

    --footer-bg: #1f2937;
    --footer-text: #d1d5db;
    --footer-muted: #9ca3af;
    --footer-border: #374151;
    --footer-accent: #34d399;

    --img-outline: transparent;
    --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.1);
}

/* System dark mode (unless user forced light) */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        color-scheme: dark;

        --bg: #1f2937;
        --bg-alt: #111827;
        --card: #374151;
        --card-border: #4b5563;

        --heading: #f9fafb;
        --text: #e5e7eb;
        --muted: #aeb6c2;

        --accent: #34d399;
        --accent-text: #34d399;
        --accent-hover: #6ee7b7;

        --btn-primary-bg: #34d399;
        --btn-primary-hover: #6ee7b7;
        --btn-primary-text: #064e3b;

        --divider: #374151;
        --input-bg: #374151;
        --input-border: #4b5563;

        --nav-bg: rgba(31, 41, 55, 0.92);
        --nav-shadow: 0 2px 10px rgba(0, 0, 0, 0.35);
        --nav-shadow-scrolled: 0 4px 20px rgba(0, 0, 0, 0.5);

        --hero-bg: linear-gradient(135deg, #113429 0%, #1f2937 65%);
        --brand-gradient: linear-gradient(160deg, #059669 0%, #047857 50%, #065f46 100%);

        --screen-bg: #111827;
        --download-card-bg: #1f2937;
        --notice-bg: rgba(16, 185, 129, 0.12);

        --footer-bg: #111827;
        --footer-text: #d1d5db;
        --footer-muted: #9ca3af;
        --footer-border: #374151;
        --footer-accent: #34d399;

        --img-outline: rgba(255, 255, 255, 0.14);
        --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.45);
    }
}

/* User forced dark mode (toggle button) */
:root[data-theme="dark"] {
    color-scheme: dark;

    --bg: #1f2937;
    --bg-alt: #111827;
    --card: #374151;
    --card-border: #4b5563;

    --heading: #f9fafb;
    --text: #e5e7eb;
    --muted: #aeb6c2;

    --accent: #34d399;
    --accent-text: #34d399;
    --accent-hover: #6ee7b7;

    --btn-primary-bg: #34d399;
    --btn-primary-hover: #6ee7b7;
    --btn-primary-text: #064e3b;

    --divider: #374151;
    --input-bg: #374151;
    --input-border: #4b5563;

    --nav-bg: rgba(31, 41, 55, 0.92);
    --nav-shadow: 0 2px 10px rgba(0, 0, 0, 0.35);
    --nav-shadow-scrolled: 0 4px 20px rgba(0, 0, 0, 0.5);

    --hero-bg: linear-gradient(135deg, #113429 0%, #1f2937 65%);
    --brand-gradient: linear-gradient(160deg, #059669 0%, #047857 50%, #065f46 100%);

    --screen-bg: #111827;
    --download-card-bg: #1f2937;
    --notice-bg: rgba(16, 185, 129, 0.12);

    --footer-bg: #111827;
    --footer-text: #d1d5db;
    --footer-muted: #9ca3af;
    --footer-border: #374151;
    --footer-accent: #34d399;

    --img-outline: rgba(255, 255, 255, 0.14);
    --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.45);
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans KR', sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
    overflow-x: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

a:focus-visible,
button:focus-visible,
select:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: var(--nav-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 1rem 0;
    box-shadow: var(--nav-shadow);
    transition: box-shadow 0.3s ease, background-color 0.3s ease;
}

.navbar.scrolled {
    box-shadow: var(--nav-shadow-scrolled);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: flex-start;
    align-items: center;
    position: relative;
}

.nav-logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-text);
}

.nav-logo i {
    margin-right: 0.5rem;
    font-size: 1.8rem;
}

.nav-logo img {
    box-shadow: 0 0 0 1px var(--img-outline);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
    margin-left: auto;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-menu a:hover {
    color: var(--accent-text);
}

.nav-menu select {
    padding: 6px 10px;
    border-radius: 8px;
    border: 1px solid var(--input-border);
    background: var(--input-bg);
    color: var(--text);
    font-family: inherit;
    font-size: 0.9rem;
    cursor: pointer;
    transition: border-color 0.3s ease, background-color 0.3s ease;
}

/* Theme toggle button */
.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.4rem;
    height: 2.4rem;
    flex-shrink: 0;
    margin-left: 1rem;
    border: 1px solid var(--input-border);
    border-radius: 50%;
    background: transparent;
    color: var(--text);
    font-size: 1rem;
    cursor: pointer;
    transition: color 0.3s ease, border-color 0.3s ease, background-color 0.3s ease;
}

.theme-toggle:hover {
    color: var(--accent-text);
    border-color: var(--accent);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    margin-left: 1rem;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text);
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: var(--hero-bg);
    padding-top: 80px;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--heading);
    margin-bottom: 1.5rem;
    line-height: 1.2;
    letter-spacing: -0.01em;
}

.hero-content p {
    font-size: 1.25rem;
    color: var(--muted);
    margin-bottom: 2rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    font-size: 1.1rem;
}

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

.btn-primary:hover {
    background: var(--btn-primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(16, 185, 129, 0.3);
}

.btn-secondary {
    background: transparent;
    color: var(--accent-text);
    border: 2px solid var(--accent);
}

.btn-secondary:hover {
    background: var(--btn-primary-bg);
    color: var(--btn-primary-text);
    transform: translateY(-2px);
}

/* Phone Mockup */
.phone-mockup {
    position: relative;
    width: 300px;
    height: 600px;
    margin: 0 auto;
    background: linear-gradient(135deg, #1f2937 0%, #111827 100%);
    border-radius: 40px;
    padding: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3), 0 0 0 1px var(--img-outline);
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: var(--screen-bg);
    border-radius: 30px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s ease;
}

.app-preview {
    text-align: center;
    padding: 2rem;
}

.preview-icon {
    font-size: 5rem;
    color: var(--accent);
    margin-bottom: 1rem;
}

.preview-icon img {
    box-shadow: 0 0 0 1px var(--img-outline);
}

.preview-text h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--heading);
    margin-bottom: 0.5rem;
}

.preview-text p {
    color: var(--muted);
    font-size: 1rem;
}

.check-button {
    margin-top: 2rem;
    padding: 1rem 2rem;
    background: var(--btn-primary-bg);
    color: var(--btn-primary-text);
    border-radius: 12px;
    font-size: 1.2rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

/* Features Section */
.features {
    padding: 6rem 0;
    background: var(--bg);
    transition: background-color 0.3s ease;
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--heading);
    letter-spacing: -0.01em;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    padding: 2rem;
    background: var(--card);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    text-align: center;
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-card);
}

.feature-icon {
    font-size: 3rem;
    color: var(--accent);
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--heading);
}

.feature-card p {
    color: var(--muted);
    line-height: 1.8;
}

/* How It Works Section */
.how-it-works {
    padding: 6rem 0;
    background: var(--bg-alt);
    transition: background-color 0.3s ease;
}

.how-it-works h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--heading);
    letter-spacing: -0.01em;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.step {
    text-align: center;
    padding: 2rem;
}

.step-number {
    width: 60px;
    height: 60px;
    background: var(--btn-primary-bg);
    color: var(--btn-primary-text);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 auto 1.5rem;
}

.step-content h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--heading);
}

.step-content p {
    color: var(--muted);
    line-height: 1.8;
}

/* Download Section */
.download {
    padding: 6rem 0;
    background: var(--brand-gradient);
    color: #ffffff;
    text-align: center;
}

.download h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    letter-spacing: -0.01em;
}

.download > .container > p {
    font-size: 1.2rem;
    margin-bottom: 3rem;
    opacity: 0.92;
}

.download-options {
    display: flex;
    gap: 2rem;
    justify-content: center;
    flex-wrap: wrap;
}

.download-card {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1.5rem 3rem;
    background: var(--download-card-bg);
    color: var(--heading);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    text-decoration: none;
    transition: all 0.3s ease;
    min-width: 250px;
}

.download-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.2);
}

.download-card i {
    font-size: 3rem;
    color: var(--accent);
}

.download-text {
    text-align: left;
}

.download-text h3 {
    font-size: 1.3rem;
    margin-bottom: 0.3rem;
}

.download-text p {
    color: var(--muted);
    font-size: 0.9rem;
}

/* Legal / FAQ pages */
.legal-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 110px 20px 60px;
    line-height: 1.8;
}

.legal-content h1 {
    color: var(--heading);
    font-size: 2rem;
    margin-bottom: 2rem;
    text-align: center;
    letter-spacing: -0.01em;
}

.legal-content h2 {
    color: var(--heading);
    font-size: 1.25rem;
    margin: 2rem 0 1rem 0;
    border-bottom: 2px solid var(--accent);
    padding-bottom: 0.5rem;
}

.legal-content p,
.legal-content li {
    margin-bottom: 1rem;
    color: var(--muted);
}

.legal-content strong {
    color: var(--text);
}

.legal-content a {
    color: var(--accent-text);
}

.legal-content ul {
    padding-left: 1.5rem;
}

.legal-content .notice {
    background: var(--notice-bg);
    border-left: 4px solid var(--accent);
    padding: 1rem 1.25rem;
    border-radius: 8px;
    color: var(--text);
}

.faq-item {
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--divider);
    padding-bottom: 1rem;
}

.faq-item h2 {
    color: var(--heading);
    font-size: 1.15rem;
    margin: 0 0 0.5rem 0;
    display: flex;
    align-items: flex-start;
    gap: 8px;
    border-bottom: none;
    padding-bottom: 0;
}

.faq-item h2 i {
    color: var(--accent);
    margin-top: 4px;
}

.faq-item p {
    color: var(--muted);
    margin: 0;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: var(--btn-primary-bg);
    color: var(--btn-primary-text);
    text-decoration: none;
    border-radius: 10px;
    font-weight: 600;
    margin-bottom: 2rem;
    transition: background-color 0.2s ease;
}

.back-link:hover {
    background: var(--btn-primary-hover);
}

/* Footer */
.footer {
    background: var(--footer-bg);
    color: var(--footer-text);
    padding: 3rem 0 1rem;
    transition: background-color 0.3s ease;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--footer-accent);
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--footer-text);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--footer-accent);
}

.footer-section p {
    color: var(--footer-text);
    margin-bottom: 0.5rem;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--footer-border);
    color: var(--footer-muted);
}

/* Responsive Design */
@media (max-width: 768px) {
    /* Off-canvas menu only on pages that have a hamburger (index pages) */
    .navbar:has(.hamburger) .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--bg);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 0;
        margin-left: 0;
    }

    .navbar:has(.hamburger) .nav-menu.active {
        left: 0;
    }

    .navbar:has(.hamburger) .theme-toggle {
        margin-left: auto;
    }

    /* Pages without hamburger: keep menu inline, allow wrapping */
    .navbar:not(:has(.hamburger)) .nav-menu {
        flex-wrap: wrap;
        gap: 1rem;
        justify-content: flex-end;
    }

    .hamburger {
        display: flex;
    }

    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }

    .hero-buttons {
        justify-content: center;
        flex-wrap: wrap;
    }

    .phone-mockup {
        width: 250px;
        height: 500px;
    }

    .features-grid,
    .steps {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 2rem;
    }

    .btn {
        padding: 0.8rem 1.5rem;
        font-size: 1rem;
    }

    .download-card {
        min-width: auto;
        width: 100%;
    }
}