/* ===================================================================
   INTERNATIONAL ACADEMIC CENTRE (IAC 教育)
   Clean, Professional Design inspired by top UK academic services
   =================================================================== */

/* ===================================================================
   ROOT VARIABLES
   =================================================================== */
:root {
    /* Colors - Clean and Professional */
    --primary: #1a365d;        /* Deep Navy Blue */
    --primary-light: #2c5282;
    --primary-dark: #0f1f3a;
    
    --accent: #d97706;         /* Professional Amber */
    --accent-light: #f59e0b;
    
    --success: #059669;
    --danger: #dc2626;
    --warning: #d97706;
    
    /* Neutrals */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-display: 'Lora', Georgia, serif;
    --font-chinese: 'Noto Sans SC', sans-serif;
    
    /* Spacing */
    --container-width: 1200px;
    --section-padding: 5rem 2rem;
    
    /* Transitions */
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-800);
    background: white;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.3;
    color: var(--primary);
    margin-bottom: 1rem;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }

p {
    margin-bottom: 1rem;
}

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

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

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

ul {
    list-style: none;
}

/* ===================================================================
   UTILITIES
   =================================================================== */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: var(--section-padding);
}

.section-light {
    background: var(--gray-50);
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 4rem;
}

.section-header h2 {
    margin-bottom: 1rem;
}

.section-header p {
    font-size: 1.125rem;
    color: var(--gray-600);
}

.highlight {
    color: var(--accent);
}

/* ===================================================================
   BUTTONS
   =================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-family: var(--font-primary);
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    border-radius: 6px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-block {
    display: flex;
    width: 100%;
    justify-content: center;
}

.btn-primary {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(26, 54, 93, 0.2);
}

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

.btn-outline:hover {
    background: var(--primary);
    color: white;
}

.btn-white {
    background: white;
    color: var(--primary);
    border-color: white;
}

.btn-white:hover {
    background: var(--gray-100);
}

.btn-outline-white {
    background: transparent;
    color: white;
    border-color: white;
}

.btn-outline-white:hover {
    background: white;
    color: var(--primary);
}

/* CTA Button in Navigation - Prominent Funnel Point */
.btn-cta-nav {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    color: white !important;
    padding: 0.65rem 1.5rem !important;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-cta-nav:hover {
    background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
    color: white !important;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.35);
}

/* ===================================================================
   NAVIGATION
   =================================================================== */
.navbar {
    background: white;
    border-bottom: 1px solid var(--gray-200);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 1rem;
    text-decoration: none;
}

.logo-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(26, 54, 93, 0.15);
}

.logo-initials {
    font-size: 1.25rem;
    font-weight: 800;
    color: white;
    letter-spacing: -0.5px;
}

.logo-text {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.logo-name {
    font-family: var(--font-display);
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1.2;
}

.logo-subtitle {
    font-family: var(--font-chinese);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--gray-600);
    letter-spacing: 0.5px;
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-toggle span {
    width: 25px;
    height: 3px;
    background: var(--primary);
    border-radius: 3px;
    transition: var(--transition);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-menu a {
    font-weight: 500;
    color: var(--gray-700);
    transition: var(--transition);
}

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

/* ===================================================================
   HERO SECTION
   =================================================================== */
.hero {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
    color: white;
    padding: 6rem 2rem;
    text-align: center;
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(220, 38, 38, 0.9);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.875rem;
    margin-bottom: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-description {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2.5rem;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 4rem;
}

.trust-bar {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    padding-top: 3rem;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.trust-item {
    text-align: center;
}

.trust-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-light);
    margin-bottom: 0.25rem;
}

.trust-label {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.8);
}

/* ===================================================================
   PROBLEM SECTION
   =================================================================== */
.problem-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-bottom: 3rem;
}

.problem-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--gray-200);
    transition: var(--transition);
}

.problem-card:hover {
    border-color: var(--primary);
    box-shadow: 0 8px 24px rgba(26, 54, 93, 0.1);
    transform: translateY(-4px);
}

.problem-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.problem-icon i {
    font-size: 1.5rem;
    color: white;
}

.problem-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.problem-stat {
    font-weight: 700;
    color: var(--danger);
    margin-bottom: 0.75rem;
}

.problem-card p {
    color: var(--gray-600);
    margin: 0;
}

.cta-box {
    background: white;
    border: 2px solid var(--primary);
    border-radius: 12px;
    padding: 3rem;
    text-align: center;
}

.cta-box h3 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
}

/* ===================================================================
   PRICING SECTION
   =================================================================== */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.pricing-card {
    background: white;
    border: 2px solid var(--gray-200);
    border-radius: 12px;
    overflow: hidden;
    transition: var(--transition);
    position: relative;
}

.pricing-card:hover {
    border-color: var(--primary);
    box-shadow: 0 12px 32px rgba(26, 54, 93, 0.15);
    transform: translateY(-8px);
}

.pricing-card-popular {
    border-color: var(--accent);
    box-shadow: 0 8px 24px rgba(217, 119, 6, 0.15);
}

.pricing-badge {
    position: absolute;
    top: 0;
    right: 0;
    background: var(--accent);
    color: white;
    padding: 0.5rem 1rem;
    font-size: 0.75rem;
    font-weight: 700;
    border-bottom-left-radius: 8px;
}

.pricing-header {
    padding: 2rem;
    text-align: center;
    border-bottom: 1px solid var(--gray-200);
}

.pricing-header h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.pricing-price {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.price-amount {
    font-size: 3rem;
    font-weight: 800;
    color: var(--primary);
    line-height: 1;
}

.price-unit {
    font-size: 0.875rem;
    color: var(--gray-600);
    margin-top: 0.5rem;
}

.pricing-body {
    padding: 2rem;
}

.pricing-description {
    text-align: center;
    color: var(--gray-600);
    margin-bottom: 1.5rem;
}

.pricing-features {
    list-style: none;
    margin-bottom: 1.5rem;
}

.pricing-features li {
    display: flex;
    align-items: start;
    gap: 0.75rem;
    padding: 0.5rem 0;
}

.pricing-features i {
    color: var(--success);
    margin-top: 0.25rem;
}

.pricing-ideal {
    background: var(--gray-100);
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
    font-size: 0.875rem;
}

.pricing-footer {
    padding: 0 2rem 2rem;
}

/* ===================================================================
   STEPS SECTION
   =================================================================== */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

.step-card {
    text-align: center;
}

.step-number {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: white;
    font-size: 2rem;
    font-weight: 800;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    box-shadow: 0 4px 12px rgba(26, 54, 93, 0.2);
}

.step-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.step-card p {
    color: var(--gray-600);
    margin: 0;
}

/* ===================================================================
   CTA SECTION
   =================================================================== */
.cta-section {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
    color: white;
    text-align: center;
}

.cta-content h2 {
    color: white;
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cta-content p {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2rem;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* ===================================================================
   FOOTER
   =================================================================== */
.footer {
    background: var(--gray-900);
    color: var(--gray-400);
    padding: 4rem 2rem 2rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.footer-logo .logo-name {
    color: white;
}

.footer-logo .logo-subtitle {
    color: var(--gray-400);
}

.footer-col h4 {
    color: white;
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

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

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

.footer-col a {
    color: var(--gray-400);
    transition: var(--transition);
}

.footer-col a:hover {
    color: white;
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid var(--gray-800);
    text-align: center;
}

.footer-bottom p {
    margin: 0.25rem 0;
}

.footer-compliance {
    font-size: 0.875rem;
    color: var(--gray-500);
}

/* ===================================================================
   RESPONSIVE DESIGN
   =================================================================== */
@media (max-width: 968px) {
    .pricing-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
        margin: 0 auto;
    }
    
    .problem-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .steps-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
    
    .trust-bar {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.25rem; }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .mobile-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 73px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        gap: 0;
        padding: 1rem;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-menu li {
        width: 100%;
    }
    
    .nav-menu a {
        display: block;
        padding: 1rem;
    }
    
    .problem-grid {
        grid-template-columns: 1fr;
    }
    
    .steps-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .btn-lg {
        width: 100%;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .trust-bar {
        grid-template-columns: 1fr 1fr;
        gap: 1.5rem;
    }
}

@media (max-width: 480px) {
    .trust-bar {
        grid-template-columns: 1fr;
    }
    
    .logo-text {
        display: none;
    }
}