/* ============================
   SmileJourney Landing Page
   ============================ */

:root {
    --color-primary: #5BBFAA;
    --color-primary-dark: #49A692;
    --color-primary-light: #7DD8C0;
    --color-bg: #FFFFFF;
    --color-bg-alt: #F8FAF9;
    --color-bg-dark: #0D1B17;
    --color-text: #1A1A1A;
    --color-text-secondary: #6B7280;
    --color-border: #E5E7EB;
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --radius: 16px;
    --radius-sm: 10px;
    --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.08);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ============================
   Typography
   ============================ */

h1 { font-size: clamp(2.25rem, 5vw, 3.5rem); font-weight: 700; line-height: 1.1; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.75rem, 4vw, 2.5rem); font-weight: 700; line-height: 1.15; letter-spacing: -0.02em; }
h3 { font-size: 1.125rem; font-weight: 600; line-height: 1.3; }
h4 { font-size: 0.8125rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--color-text-secondary); }

.section-title {
    text-align: center;
    margin-bottom: 12px;
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-secondary);
    font-size: 1.125rem;
    max-width: 520px;
    margin: 0 auto 56px;
}

.gradient-text {
    background: linear-gradient(135deg, var(--color-primary), #3AAFA9);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ============================
   Buttons
   ============================ */

.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 28px;
    border-radius: 12px;
    font-family: var(--font);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

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

.btn-primary:hover {
    background: #333;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.btn-lg {
    padding: 16px 32px;
    font-size: 1.0625rem;
}

/* App Store Badge */
.app-store-badge {
    display: inline-block;
    transition: var(--transition);
}

.app-store-badge:hover {
    opacity: 0.85;
    transform: translateY(-1px);
}

.app-store-badge img {
    height: 54px;
    width: auto;
}

/* ============================
   Navigation
   ============================ */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid transparent;
    transition: var(--transition);
}

.navbar.scrolled {
    border-bottom-color: var(--color-border);
}

.nav-container {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--color-text);
    font-weight: 700;
    font-size: 1.125rem;
}

.nav-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a {
    text-decoration: none;
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    font-weight: 500;
    transition: var(--transition);
}

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

.nav-cta {
    background: var(--color-text);
    color: #fff !important;
    padding: 8px 20px;
    border-radius: 8px;
}

.nav-cta:hover {
    background: #333 !important;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: var(--transition);
}

/* ============================
   Hero
   ============================ */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 100px 24px 60px;
    max-width: 1120px;
    margin: 0 auto;
    gap: 60px;
}

.hero-content {
    flex: 1;
    max-width: 560px;
}

.hero-subtitle {
    color: var(--color-text-secondary);
    font-size: 1.1875rem;
    margin: 20px 0 36px;
    line-height: 1.6;
}

.hero-trust {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-top: 20px;
    padding: 8px 16px;
    background: rgba(91, 191, 170, 0.1);
    border: 1px solid rgba(91, 191, 170, 0.25);
    border-radius: 100px;
    color: var(--color-primary-dark);
    font-size: 0.875rem;
    font-weight: 600;
}

.hero-trust svg {
    flex-shrink: 0;
    color: var(--color-primary);
}

.hero-visual {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Phone Mockup */
.phone-mockup {
    perspective: 1000px;
}

.phone-frame {
    width: 280px;
    height: 570px;
    background: #1A1A1A;
    border-radius: 40px;
    padding: 12px;
    box-shadow:
        0 0 0 1px rgba(255,255,255,0.1),
        0 20px 60px rgba(0,0,0,0.2),
        0 0 0 8px #0D0D0D;
    transform: rotateY(-4deg) rotateX(2deg);
    transition: transform 0.6s ease;
}

.phone-frame:hover {
    transform: rotateY(0deg) rotateX(0deg);
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: linear-gradient(165deg, #0F2823, #0D1B17);
    border-radius: 30px;
    overflow: hidden;
    padding: 48px 20px 20px;
}

/* Mock App UI */
.mock-app {
    display: flex;
    flex-direction: column;
    gap: 16px;
    height: 100%;
}

.mock-header {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.mock-greeting {
    font-size: 0.75rem;
    color: rgba(255,255,255,0.5);
}

.mock-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: #fff;
}

.mock-tray-card {
    background: rgba(255,255,255,0.08);
    border-radius: 16px;
    padding: 16px;
    border: 1px solid rgba(255,255,255,0.06);
}

.mock-tray-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.mock-label {
    font-size: 0.75rem;
    color: rgba(255,255,255,0.5);
}

.mock-tray-number {
    font-size: 1.25rem;
    font-weight: 700;
    color: #fff;
}

.mock-tray-number small {
    font-size: 0.75rem;
    font-weight: 400;
    color: rgba(255,255,255,0.4);
}

.mock-progress-bar {
    height: 6px;
    background: rgba(255,255,255,0.1);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: 8px;
}

.mock-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-primary-light));
    border-radius: 3px;
    transition: width 1.5s ease;
}

.mock-percent {
    font-size: 0.6875rem;
    color: var(--color-primary-light);
}

.mock-wear-card {
    background: rgba(255,255,255,0.08);
    border-radius: 16px;
    padding: 16px;
    border: 1px solid rgba(255,255,255,0.06);
    position: relative;
}

.mock-wear-label {
    font-size: 0.75rem;
    color: rgba(255,255,255,0.5);
    display: block;
    margin-bottom: 4px;
}

.mock-wear-time {
    font-size: 1.75rem;
    font-weight: 700;
    color: #fff;
}

.mock-wear-ring {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    width: 48px;
    height: 48px;
}

.mock-wear-ring svg {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.mock-actions {
    display: flex;
    gap: 10px;
    margin-top: auto;
}

.mock-action-btn {
    flex: 1;
    background: rgba(91, 191, 170, 0.15);
    color: var(--color-primary-light);
    border-radius: 12px;
    padding: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.mock-action-btn span {
    font-size: 1.25rem;
}

/* ============================
   Trust Banner
   ============================ */

.trust-banner {
    padding: 64px 0;
    background: var(--color-bg-dark);
    color: #fff;
}

.trust-headline {
    text-align: center;
    margin-bottom: 40px;
}

.trust-headline h2 {
    font-size: clamp(1.5rem, 3.5vw, 2rem);
    font-weight: 700;
    color: #fff;
    margin-bottom: 8px;
}

.trust-headline p {
    font-size: 1.0625rem;
    color: rgba(255, 255, 255, 0.6);
}

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

.trust-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 16px;
    padding: 32px 24px;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius);
}

.trust-item-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(91, 191, 170, 0.15);
    border-radius: 50%;
}

.trust-item svg {
    flex-shrink: 0;
    color: var(--color-primary-light);
}

.trust-item div {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.trust-item strong {
    font-size: 1.125rem;
    font-weight: 700;
    color: #fff;
}

.trust-item span {
    font-size: 0.9375rem;
    color: rgba(255, 255, 255, 0.55);
    line-height: 1.5;
}

/* ============================
   Features
   ============================ */

.features {
    padding: 100px 0;
    background: var(--color-bg-alt);
}

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

.feature-card {
    background: var(--color-bg);
    border-radius: var(--radius);
    padding: 32px 28px;
    border: 1px solid var(--color-border);
    transition: var(--transition);
    opacity: 0;
    transform: translateY(20px);
}

.feature-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.feature-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
    border-color: transparent;
}

.feature-card.visible:hover {
    transform: translateY(-2px);
}

.feature-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(91, 191, 170, 0.1);
    color: var(--color-primary);
    border-radius: 12px;
    margin-bottom: 16px;
}

.feature-card h3 {
    margin-bottom: 8px;
}

.feature-card p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    line-height: 1.6;
}

/* ============================
   How It Works
   ============================ */

.how-it-works {
    padding: 100px 0;
}

.steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    margin-top: 56px;
}

.step {
    text-align: center;
}

.step-number {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), #3AAFA9);
    color: #fff;
    font-weight: 700;
    font-size: 1.25rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.step h3 {
    margin-bottom: 10px;
}

.step p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    max-width: 300px;
    margin: 0 auto;
}

/* ============================
   Download CTA
   ============================ */

.download {
    padding: 40px 0 100px;
}

.download-card {
    background: var(--color-bg-dark);
    border-radius: 24px;
    padding: 64px 40px;
    text-align: center;
    color: #fff;
}

.download-icon {
    width: 80px;
    height: 80px;
    border-radius: 20px;
    margin-bottom: 24px;
}

.download-card h2 {
    margin-bottom: 12px;
}

.download-card p {
    color: rgba(255,255,255,0.6);
    font-size: 1.0625rem;
    margin-bottom: 32px;
}

.download-card .btn-primary {
    background: #fff;
    color: var(--color-bg-dark);
}

.download-card .btn-primary:hover {
    background: #f0f0f0;
}

/* ============================
   Contact
   ============================ */

.contact {
    padding: 100px 0;
    background: var(--color-bg-alt);
}

.contact-form {
    max-width: 480px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
    font-family: var(--font);
    font-size: 1rem;
    background: var(--color-bg);
    color: var(--color-text);
    transition: var(--transition);
    outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(91, 191, 170, 0.15);
}

.form-group input.error,
.form-group textarea.error {
    border-color: #EF4444;
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.btn-submit {
    width: 100%;
    justify-content: center;
}

.form-message {
    text-align: center;
    padding: 12px;
    border-radius: var(--radius-sm);
    font-size: 0.9375rem;
    font-weight: 500;
}

.form-message.success {
    background: rgba(91, 191, 170, 0.1);
    color: var(--color-primary-dark);
}

.form-message.error {
    background: rgba(239, 68, 68, 0.1);
    color: #DC2626;
}

/* ============================
   Footer
   ============================ */

.footer {
    background: var(--color-bg-dark);
    color: rgba(255,255,255,0.6);
    padding: 64px 0 32px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 48px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
    color: #fff;
    font-weight: 700;
    font-size: 1.125rem;
}

.footer-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
}

.footer-brand p {
    font-size: 0.9375rem;
}

.footer-col {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-col h4 {
    color: rgba(255,255,255,0.4);
    margin-bottom: 4px;
}

.footer-col a {
    color: rgba(255,255,255,0.6);
    text-decoration: none;
    font-size: 0.9375rem;
    transition: var(--transition);
}

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

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.08);
    padding-top: 24px;
    font-size: 0.8125rem;
}

/* ============================
   Value Proposition
   ============================ */

.value-proposition {
    padding: 100px 0;
    background: var(--color-bg-alt);
}

.value-statement {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 48px;
}

.value-context {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    margin-bottom: 4px;
}

.value-treatment-price {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: -0.02em;
    margin-bottom: 28px;
    opacity: 0.3;
    text-decoration: line-through;
    text-decoration-color: var(--color-text-secondary);
}

.value-app-price {
    font-size: clamp(3rem, 7vw, 4.5rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    background: linear-gradient(135deg, var(--color-primary), #3AAFA9);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 12px;
    line-height: 1.1;
}

.value-app-price span {
    font-size: clamp(1.25rem, 2.5vw, 1.75rem);
    font-weight: 500;
}

.value-tagline {
    font-size: 1rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.value-features {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
    max-width: 700px;
    margin: 0 auto;
}

.value-feature {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 100px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text);
}

.value-feature svg {
    color: var(--color-primary);
    flex-shrink: 0;
}

/* ============================
   FAQ
   ============================ */

.faq {
    padding: 100px 0;
}

.faq-list {
    max-width: 720px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 0;
}

.faq-item {
    border-bottom: 1px solid var(--color-border);
}

.faq-item:first-child {
    border-top: 1px solid var(--color-border);
}

.faq-item summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 0;
    font-size: 1.0625rem;
    font-weight: 600;
    cursor: pointer;
    list-style: none;
    color: var(--color-text);
    transition: var(--transition);
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: "+";
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--color-text-secondary);
    flex-shrink: 0;
    margin-left: 16px;
    transition: var(--transition);
}

.faq-item[open] summary::after {
    content: "\2212";
}

.faq-item summary:hover {
    color: var(--color-primary-dark);
}

.faq-answer {
    padding: 0 0 20px;
}

.faq-answer p {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
}

/* ============================
   Responsive
   ============================ */

@media (max-width: 900px) {
    .hero {
        flex-direction: column;
        text-align: center;
        padding-top: 120px;
        min-height: auto;
        gap: 48px;
    }

    .hero-content {
        max-width: 100%;
    }

    .hero-actions {
        justify-content: center;
        display: flex;
    }

    .trust-items {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .steps {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }
}

@media (max-width: 640px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 24px;
        gap: 20px;
        border-bottom: 1px solid var(--color-border);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }

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

    .phone-frame {
        width: 240px;
        height: 490px;
    }

    .download-card {
        padding: 48px 24px;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 28px;
    }
}