/* ========================================
   DeltaAlgo Landing Page Styles
   ======================================== */

/* CSS Variables */
:root {
    /* Colors - Matching App Theme */
    --bg-primary: #0a0a0f;
    --bg-card: #1a1a2e;
    --bg-elevated: #252540;
    --primary: #e91e8c;
    --primary-dark: #c4167a;
    --secondary: #00d4ff;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-muted: #6b6b80;
    --success: #00c853;
    --warning: #ffab00;
    --border: #2a2a3e;
    --gradient: linear-gradient(135deg, #e91e8c, #00d4ff);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-display: 'Poppins', sans-serif;
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    --spacing-3xl: 64px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(233, 30, 140, 0.3);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

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

ul, ol {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* Gradient Text */
.gradient-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: all var(--transition-normal);
    cursor: pointer;
}

.btn--primary {
    background: var(--gradient);
    color: var(--text-primary);
    box-shadow: var(--shadow-glow);
}

.btn--primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 60px rgba(233, 30, 140, 0.4);
}

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

.btn--outline:hover {
    border-color: var(--secondary);
    color: var(--secondary);
}

.btn--sm {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 14px;
}

.btn--lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 16px;
}

.btn--xl {
    padding: var(--spacing-lg) var(--spacing-2xl);
    font-size: 18px;
}

.btn--full {
    width: 100%;
}

/* Section Header */
.section__header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section__title {
    font-family: var(--font-display);
    font-size: clamp(28px, 5vw, 42px);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.section__subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ========================================
   Header / Navigation
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: var(--spacing-md) 0;
    transition: all var(--transition-normal);
}

.header.scrolled {
    background: rgba(10, 10, 15, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
}

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

.nav__logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-display);
    font-size: 24px;
    font-weight: 700;
}

.nav__logo-img {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
}

.nav__list {
    display: flex;
    gap: var(--spacing-xl);
}

.nav__link {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.nav__link:hover {
    color: var(--text-primary);
}

.nav__link--highlight {
    color: var(--primary);
}

.nav__link--highlight:hover {
    color: var(--secondary);
}

.nav__actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.nav__toggle,
.nav__close {
    display: none;
    font-size: 24px;
    color: var(--text-primary);
}

/* Mobile Navigation */
@media (max-width: 768px) {
    .nav__menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 300px;
        height: 100vh;
        background: var(--bg-card);
        padding: var(--spacing-3xl) var(--spacing-lg);
        transition: right var(--transition-normal);
        z-index: 1001;
    }
    
    .nav__menu.active {
        right: 0;
    }
    
    .nav__list {
        flex-direction: column;
        gap: var(--spacing-lg);
    }
    
    .nav__link {
        font-size: 18px;
    }
    
    .nav__toggle {
        display: block;
    }
    
    .nav__close {
        display: block;
        position: absolute;
        top: var(--spacing-lg);
        right: var(--spacing-lg);
    }
    
    .nav__actions .btn {
        display: none;
    }
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 var(--spacing-3xl);
    position: relative;
    overflow: hidden;
}

.hero__container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.hero__title {
    font-family: var(--font-display);
    font-size: clamp(36px, 6vw, 64px);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-lg);
}

.hero__description {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 500px;
}

.hero__buttons {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-2xl);
    flex-wrap: wrap;
}

.hero__stats {
    display: flex;
    gap: var(--spacing-2xl);
}

.hero__stat {
    text-align: center;
}

.hero__stat-value {
    display: block;
    font-family: var(--font-display);
    font-size: 28px;
    font-weight: 700;
    color: var(--secondary);
}

.hero__stat-label {
    font-size: 14px;
    color: var(--text-muted);
}

.hero__image {
    display: flex;
    justify-content: center;
}

.phone-mockup {
    position: relative;
    width: 280px;
    animation: float 6s ease-in-out infinite;
}

.phone-mockup__img {
    width: 100%;
    border-radius: 32px;
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.hero__bg {
    position: absolute;
    top: 0;
    right: 0;
    width: 60%;
    height: 100%;
    background: radial-gradient(circle at 70% 30%, rgba(233, 30, 140, 0.15) 0%, transparent 50%),
                radial-gradient(circle at 90% 80%, rgba(0, 212, 255, 0.1) 0%, transparent 40%);
    pointer-events: none;
    z-index: -1;
}

@media (max-width: 768px) {
    .hero__container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero__description {
        margin: 0 auto var(--spacing-xl);
    }
    
    .hero__buttons {
        justify-content: center;
    }
    
    .hero__stats {
        justify-content: center;
    }
    
    .hero__image {
        order: -1;
    }
    
    .phone-mockup {
        width: 220px;
    }
}

/* ========================================
   Features Section
   ======================================== */
.features {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-card);
}

.features__grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-lg);
}

.feature-card {
    background: var(--bg-elevated);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border);
    text-align: center;
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary);
    box-shadow: var(--shadow-glow);
}

.feature-card__icon {
    font-size: 48px;
    margin-bottom: var(--spacing-md);
}

.feature-card__title {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.feature-card__description {
    font-size: 14px;
    color: var(--text-secondary);
}

@media (max-width: 1024px) {
    .features__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

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

/* ========================================
   How It Works Section
   ======================================== */
.how-it-works {
    padding: var(--spacing-3xl) 0;
}

.steps {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.step {
    flex: 1;
    min-width: 180px;
    max-width: 200px;
    text-align: center;
}

.step__number {
    width: 48px;
    height: 48px;
    background: var(--gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 700;
    margin: 0 auto var(--spacing-md);
}

.step__title {
    font-family: var(--font-display);
    font-size: 18px;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.step__description {
    font-size: 14px;
    color: var(--text-secondary);
}

.step__connector {
    width: 40px;
    height: 2px;
    background: var(--border);
    margin-top: 24px;
}

@media (max-width: 768px) {
    .steps {
        flex-direction: column;
        align-items: center;
    }
    
    .step__connector {
        width: 2px;
        height: 24px;
        margin: 0;
    }
}

/* ========================================
   Screenshots Section
   ======================================== */
.screenshots {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-card);
}

.screenshots__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
    justify-items: center;
}

.screenshot {
    text-align: center;
}

.screenshot__img {
    width: 240px;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    transition: transform var(--transition-normal);
}

.screenshot:hover .screenshot__img {
    transform: scale(1.05);
}

.screenshot__label {
    margin-top: var(--spacing-md);
    font-weight: 500;
    color: var(--text-secondary);
}

@media (max-width: 768px) {
    .screenshots__grid {
        grid-template-columns: 1fr;
    }
    
    .screenshot__img {
        width: 200px;
    }
}

/* ========================================
   Referral Section
   ======================================== */
.referral {
    padding: var(--spacing-3xl) 0;
}

.referral__card {
    background: linear-gradient(135deg, rgba(233, 30, 140, 0.1), rgba(0, 212, 255, 0.1));
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-3xl);
}

.referral__flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
    flex-wrap: wrap;
}

.referral__step {
    text-align: center;
    padding: var(--spacing-lg);
    background: var(--bg-elevated);
    border-radius: var(--radius-lg);
    min-width: 150px;
}

.referral__step-icon {
    font-size: 40px;
    margin-bottom: var(--spacing-sm);
}

.referral__step-title {
    font-family: var(--font-display);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.referral__step-desc {
    font-size: 13px;
    color: var(--text-secondary);
}

.referral__arrow {
    font-size: 24px;
    color: var(--secondary);
}

.referral__info {
    background: var(--bg-card);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    max-width: 500px;
    margin: 0 auto var(--spacing-xl);
}

.referral__info h4 {
    font-family: var(--font-display);
    margin-bottom: var(--spacing-md);
}

.referral__info ol {
    list-style: decimal;
    padding-left: var(--spacing-lg);
}

.referral__info li {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

.referral__highlight {
    text-align: center;
    font-size: 18px;
    color: var(--secondary);
}

@media (max-width: 768px) {
    .referral__flow {
        flex-direction: column;
    }
    
    .referral__arrow {
        transform: rotate(90deg);
    }
}

/* ========================================
   Pricing Section
   ======================================== */
.pricing {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-card);
}

.pricing__card {
    max-width: 400px;
    margin: 0 auto;
    background: var(--bg-elevated);
    border: 2px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.pricing__badge {
    position: absolute;
    top: 20px;
    right: -30px;
    background: var(--gradient);
    color: var(--text-primary);
    font-size: 12px;
    font-weight: 600;
    padding: var(--spacing-xs) var(--spacing-2xl);
    transform: rotate(45deg);
}

.pricing__price {
    margin: var(--spacing-xl) 0;
}

.pricing__currency {
    font-size: 24px;
    vertical-align: top;
}

.pricing__amount {
    font-family: var(--font-display);
    font-size: 64px;
    font-weight: 800;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.pricing__period {
    font-size: 16px;
    color: var(--text-secondary);
}

.pricing__features {
    text-align: left;
    margin-bottom: var(--spacing-xl);
}

.pricing__feature {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--border);
}

.pricing__feature:last-child {
    border-bottom: none;
}

.pricing__check {
    color: var(--success);
    font-weight: bold;
}

.pricing__feature--highlight {
    color: var(--secondary);
    font-weight: 500;
}

.pricing__note {
    margin-top: var(--spacing-md);
    font-size: 14px;
    color: var(--secondary);
}

.pricing__tagline {
    text-align: center;
    margin-top: var(--spacing-2xl);
    color: var(--text-secondary);
}

/* ========================================
   FAQ Section
   ======================================== */
.faq {
    padding: var(--spacing-3xl) 0;
}

.faq__list {
    max-width: 700px;
    margin: 0 auto;
}

.faq__item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-md);
    overflow: hidden;
}

.faq__question {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    font-size: 16px;
    font-weight: 500;
    color: var(--text-primary);
    text-align: left;
    transition: background var(--transition-fast);
}

.faq__question:hover {
    background: var(--bg-elevated);
}

.faq__icon {
    font-size: 24px;
    color: var(--secondary);
    transition: transform var(--transition-normal);
}

.faq__item.active .faq__icon {
    transform: rotate(45deg);
}

.faq__answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
}

.faq__item.active .faq__answer {
    max-height: 500px;
}

.faq__answer p {
    padding: 0 var(--spacing-lg) var(--spacing-lg);
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========================================
   Download Section
   ======================================== */
.download {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-card);
}

.download__card {
    background: linear-gradient(135deg, rgba(233, 30, 140, 0.15), rgba(0, 212, 255, 0.1));
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-3xl);
}

.download__content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-3xl);
    flex-wrap: wrap;
}

.download__qr {
    text-align: center;
}

.download__qr-img {
    width: 180px;
    height: 180px;
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
}

.download__qr-text {
    margin-top: var(--spacing-sm);
    color: var(--text-secondary);
    font-size: 14px;
}

.download__info {
    text-align: center;
}

.download__btn {
    flex-direction: column;
    padding: var(--spacing-lg) var(--spacing-3xl);
}

.download__btn-icon {
    font-size: 32px;
}

.download__btn-text {
    display: flex;
    flex-direction: column;
}

.download__btn-text strong {
    font-size: 18px;
}

.download__btn-text small {
    font-size: 12px;
    opacity: 0.8;
}

.download__note {
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md);
    background: rgba(255, 171, 0, 0.1);
    border: 1px solid var(--warning);
    border-radius: var(--radius-md);
    font-size: 14px;
}

.download__referral {
    margin-top: var(--spacing-md);
    font-size: 16px;
    color: var(--secondary);
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background: var(--bg-primary);
    padding: var(--spacing-3xl) 0 var(--spacing-lg);
    border-top: 1px solid var(--border);
}

.footer__grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

.footer__logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-display);
    font-size: 24px;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.footer__logo-img {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
}

.footer__tagline {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

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

.footer__company a {
    color: var(--secondary);
    transition: color var(--transition-fast);
}

.footer__company a:hover {
    color: var(--primary);
}

.footer__title {
    font-family: var(--font-display);
    font-size: 16px;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.footer__links ul li,
.footer__contact ul li {
    margin-bottom: var(--spacing-sm);
}

.footer__links a {
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.footer__links a:hover {
    color: var(--secondary);
}

.footer__contact ul li {
    color: var(--text-secondary);
}

.footer__contact a {
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.footer__contact a:hover {
    color: var(--secondary);
}

.footer__address {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.6;
}

.footer__address p {
    color: var(--text-secondary);
}

.footer__bottom {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

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

.footer__copyright a {
    color: var(--secondary);
    transition: color var(--transition-fast);
}

.footer__copyright a:hover {
    color: var(--primary);
}

.footer__legal {
    display: flex;
    gap: var(--spacing-lg);
}

.footer__legal a {
    color: var(--text-muted);
    font-size: 14px;
    transition: color var(--transition-fast);
}

.footer__legal a:hover {
    color: var(--secondary);
}

@media (max-width: 768px) {
    .footer__grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer__logo {
        justify-content: center;
    }
    
    .footer__bottom {
        flex-direction: column;
        text-align: center;
    }
}

/* ========================================
   Animations
   ======================================== */
[data-aos="fade-up"] {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-aos="fade-up"].aos-animate {
    opacity: 1;
    transform: translateY(0);
}

[data-aos="fade-right"] {
    opacity: 0;
    transform: translateX(-30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-aos="fade-right"].aos-animate {
    opacity: 1;
    transform: translateX(0);
}

[data-aos="fade-left"] {
    opacity: 0;
    transform: translateX(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-aos="fade-left"].aos-animate {
    opacity: 1;
    transform: translateX(0);
}

[data-aos="zoom-in"] {
    opacity: 0;
    transform: scale(0.9);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-aos="zoom-in"].aos-animate {
    opacity: 1;
    transform: scale(1);
}

/* Delay classes */
[data-aos-delay="100"] { transition-delay: 0.1s; }
[data-aos-delay="200"] { transition-delay: 0.2s; }
[data-aos-delay="300"] { transition-delay: 0.3s; }
[data-aos-delay="400"] { transition-delay: 0.4s; }