/* ========================================
   RESET & BASE STYLES
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

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

/* ========================================
   UTILITY CLASSES
   ======================================== */
.icon {
    min-width: 24px;
    text-align: center;
}

.icon-list {
    list-style: none;
    padding-left: 0;
}

.icon-list li {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

/* ========================================
   HEADER & NAVIGATION
   ======================================== */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 10;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.top-header {
    text-align: center;
    margin-bottom: 30px;
}

.top-header h1 {
    color: #333;
    font-size: 2.5rem;
    margin-bottom: 10px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.top-header p {
    color: #666;
    font-size: 1.1rem;
}

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

.logo {
    font-size: 2rem;
    font-weight: bold;
    background: linear-gradient(45deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    z-index: 101;
}

/* ========================================
   MOBILE MENU
   ======================================== */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 25px;
    background: none;
    border: none;
    cursor: pointer;
    z-index: 101;
    position: relative;
}

.hamburger-line {
    width: 100%;
    height: 3px;
    background: linear-gradient(45deg, #667eea, #764ba2);
    border-radius: 2px;
    transition: all 0.3s ease;
    transform-origin: center;
}

.mobile-menu-btn.active .hamburger-line:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-btn.active .hamburger-line:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active .hamburger-line:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* ========================================
   DESKTOP NAVIGATION
   ======================================== */
.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links a:hover {
    color: #667eea;
    transform: translateY(-2px);
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background: linear-gradient(45deg, #667eea, #764ba2);
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}

/* ========================================
   MOBILE NAVIGATION OVERLAY
   ======================================== */
.mobile-nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: rgba(102, 126, 234, 0.98);
    backdrop-filter: blur(20px);
    z-index: 99;
    opacity: 0;
    visibility: hidden;
    transition: all 0.4s ease;
}

.mobile-nav-overlay.active {
    opacity: 1;
    visibility: visible;
}

.mobile-nav-menu {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100%;
    gap: 3rem;
}

.mobile-nav-menu a {
    color: white;
    text-decoration: none;
    font-size: 2rem;
    font-weight: 600;
    text-align: center;
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.5s ease;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.mobile-nav-overlay.active .mobile-nav-menu a {
    opacity: 1;
    transform: translateY(0);
}

.mobile-nav-menu a:nth-child(1) { transition-delay: 0.1s; }
.mobile-nav-menu a:nth-child(2) { transition-delay: 0.2s; }
.mobile-nav-menu a:nth-child(3) { transition-delay: 0.3s; }
.mobile-nav-menu a:nth-child(4) { transition-delay: 0.4s; }

.mobile-nav-menu a:hover {
    color: #f0f0f0;
    transform: scale(1.1);
}

.mobile-nav-menu .icon {
    font-size: 2.5rem;
}

/* ========================================
   HERO SECTION
   ======================================== */
.hero {
    padding: 2rem 0;
    text-align: center;
    color: white;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    animation: fadeInUp 1s ease-out;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease-out 0.2s both;
}

/* ========================================
   APP SECTION
   ======================================== */
.app-section {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-radius: 30px;
    padding: 4rem 2rem;
    margin: 3rem 0;
    text-align: center;
    color: #333;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    position: relative;
}

.hero + .app-section,
.header + main > .app-section {
    margin-top: -4rem;
    position: relative;
    z-index: 1;
}

.app-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: linear-gradient(90deg, #667eea, #764ba2, #667eea);
    animation: shimmer 3s ease-in-out infinite;
}

.app-section h2 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    background: linear-gradient(45deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: none;
}

.app-section > p {
    font-size: 1.3rem;
    color: #666;
    margin-bottom: 3rem;
}

/* ========================================
   APP SHOWCASE
   ======================================== */
.app-showcase {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    margin: 3rem 0;
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
}

.app-image-container {
    position: relative;
}

.app-image {
    width: 100%;
    max-width: none;
    border-radius: 25px;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.4);
    transition: all 0.4s ease;
    animation: float 6s ease-in-out infinite;
}

.app-image:hover {
    transform: scale(1.05) rotate(-2deg);
    box-shadow: 0 35px 70px rgba(0, 0, 0, 0.5);
}

/* ========================================
   DOWNLOAD SECTION
   ======================================== */
.download-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}

.qr-code {
    width: 250px;
    height: 250px;
    border-radius: 20px;
    background: white;
    padding: 20px;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
}

.qr-code:hover {
    transform: scale(1.1);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.download-text {
    font-size: 1.2rem;
    color: #555;
    margin: 1rem 0;
}

/* ========================================
   BUTTON STYLES
   ======================================== */
.btn {
    display: inline-block;
    padding: 16px 40px;
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.4);
    position: relative;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s ease;
}

.btn:hover::before {
    left: 100%;
}

.btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 30px rgba(102, 126, 234, 0.6);
}

.app-note {
    background: linear-gradient(45deg, #f093fb 0%, #f5576c 100%);
    color: white;
    padding: 1rem 2rem;
    border-radius: 50px;
    margin-top: 2rem;
    font-size: 0.9rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

/* ========================================
   THAI ALPHABET SECTION
   ======================================== */
.alphabet-section {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 3rem;
    margin: 2rem 0;
}

.alphabet-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(60px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.thai-char {
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    font-size: 2rem;
    font-weight: bold;
    text-align: center;
    padding: 1rem;
    border-radius: 10px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.thai-char:hover {
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

/* ========================================
   FOOTER
   ======================================== */
.footer {
    background: rgba(0, 0, 0, 0.8);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    color: white;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    color: white;
    font-size: 1.5rem;
    transition: all 0.3s ease;
}

.social-links a:hover {
    color: #667eea;
    transform: translateY(-3px);
}

/* ========================================
   ANIMATIONS
   ======================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes shimmer {
    0%, 100% {
        opacity: 0.8;
    }
    50% {
        opacity: 1;
    }
}

/* ========================================
   RESPONSIVE DESIGN - TABLET & MOBILE
   ======================================== */
@media (max-width: 768px) {
    .logo {
        font-size: 1.5rem;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .nav-links {
        display: none;
    }

    .mobile-nav-overlay {
        display: block;
    }

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

    .hero p {
        font-size: 1rem;
        padding: 0 1rem;
    }

    .app-showcase {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .app-section {
        padding: 2rem 1rem;
        border-radius: 20px;
    }

    .app-section h2 {
        font-size: 2.2rem;
    }

    .app-section > p {
        font-size: 1.1rem;
    }

    .app-image {
        max-width: 300px;
    }

    .qr-code {
        width: 200px;
        height: 200px;
    }

    .alphabet-section {
        padding: 2rem 1rem;
    }

    .alphabet-grid {
        grid-template-columns: repeat(auto-fit, minmax(50px, 1fr));
        gap: 0.5rem;
    }

    .thai-char {
        font-size: 1.5rem;
        padding: 0.8rem;
    }

    .btn {
        padding: 14px 30px;
        font-size: 1rem;
    }
}

/* ========================================
   RESPONSIVE DESIGN - SMALL MOBILE
   ======================================== */
@media (max-width: 480px) {
    .logo {
        font-size: 1.3rem;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .app-section h2 {
        font-size: 1.8rem;
    }

    .mobile-nav-menu a {
        font-size: 1.5rem;
    }

    .mobile-nav-menu .icon {
        font-size: 2rem;
    }

    .qr-code {
        width: 180px;
        height: 180px;
    }

    .app-image {
        max-width: 250px;
    }
}