:root {
    /* Color Palette - HSL */
    --primary: 228, 81%, 59%;      /* Indigo */
    --primary-hover: 228, 70%, 50%;
    --secondary: 210, 29%, 24%;    /* Dark Navy */
    
    --bg-main: 210, 40%, 98%;      /* Very light grayish blue */
    --bg-surface: 0, 0%, 100%;     /* White */
    --bg-surface-hover: 210, 20%, 96%;
    
    --text-main: 215, 25%, 27%;
    --text-muted: 215, 15%, 50%;
    
    --border: 214, 32%, 91%;
    --success: 152, 69%, 31%;
    --danger: 354, 70%, 54%;

    /* Typography */
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    
    /* Spacing */
    --spacing-1: 0.25rem;
    --spacing-2: 0.5rem;
    --spacing-3: 0.75rem;
    --spacing-4: 1rem;
    --spacing-6: 1.5rem;
    --spacing-8: 2rem;
    --spacing-12: 3rem;
    --spacing-16: 4rem;
    
    /* Radii */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

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

body {
    font-family: var(--font-sans);
    background-color: hsl(var(--bg-main));
    color: hsl(var(--text-main));
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.2s;
}

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

ul {
    list-style: none;
}

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

/* Layout Utilities */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-4);
}

.flex { display: flex; }
.flex-col { display: flex; flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-2 { gap: var(--spacing-2); }
.gap-4 { gap: var(--spacing-4); }
.gap-6 { gap: var(--spacing-6); }
.gap-8 { gap: var(--spacing-8); }

.grid { display: grid; }
.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.text-center { text-align: center; }
.text-muted { color: hsl(var(--text-muted)); }
.text-sm { font-size: 0.875rem; }
.text-lg { font-size: 1.125rem; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

.mt-2 { margin-top: var(--spacing-2); }
.mt-4 { margin-top: var(--spacing-4); }
.mt-8 { margin-top: var(--spacing-8); }
.mb-4 { margin-bottom: var(--spacing-4); }
.mb-8 { margin-bottom: var(--spacing-8); }
.py-8 { padding-top: var(--spacing-8); padding-bottom: var(--spacing-8); }
.py-16 { padding-top: var(--spacing-16); padding-bottom: var(--spacing-16); }

/* Components */
/* Header */
.header {
    background-color: hsl(var(--bg-surface));
    border-bottom: 1px solid hsl(var(--border));
    position: sticky;
    top: 0;
    z-index: 50;
}

.nav {
    height: 4rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: hsl(var(--primary));
    letter-spacing: -0.025em;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links {
    display: flex;
    gap: var(--spacing-6);
}

.nav-link {
    font-weight: 500;
    color: hsl(var(--text-muted));
}

.nav-link:hover, .nav-link.active {
    color: hsl(var(--primary));
}

.mobile-menu-btn {
    display: none;
    font-size: 1.5rem;
    color: hsl(var(--text-main));
}

/* Button */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2) var(--spacing-4);
    border-radius: var(--radius-md);
    font-weight: 500;
    transition: all 0.2s;
    gap: 0.5rem;
}

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

.btn-primary:hover {
    background-color: hsl(var(--primary-hover));
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    border: 1px solid hsl(var(--border));
    background-color: transparent;
}

.btn-outline:hover {
    background-color: hsl(var(--bg-surface-hover));
}

/* Hero Section */
.hero {
    background: linear-gradient(to bottom, hsl(var(--bg-surface)), hsl(var(--bg-main)));
    padding: var(--spacing-16) 0;
    border-bottom: 1px solid hsl(var(--border));
}

.hero h1 {
    font-size: 3rem;
    line-height: 1.2;
    letter-spacing: -0.025em;
    color: hsl(var(--secondary));
    margin-bottom: var(--spacing-4);
}

.hero p {
    font-size: 1.25rem;
    color: hsl(var(--text-muted));
    max-width: 600px;
    margin: 0 auto var(--spacing-8);
}

/* Cards */
.card {
    background-color: hsl(var(--bg-surface));
    border-radius: var(--radius-lg);
    border: 1px solid hsl(var(--border));
    padding: var(--spacing-6);
    transition: all 0.3s;
    box-shadow: var(--shadow-sm);
}

.card:hover {
    box-shadow: var(--shadow-md);
    border-color: hsl(var(--primary), 0.3);
}

.country-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-4);
    text-decoration: none;
}

.flag {
    width: 48px;
    height: 32px;
    border-radius: var(--radius-sm);
    object-fit: cover;
    box-shadow: 0 0 0 1px hsl(var(--border));
}

.country-info h3 {
    font-size: 1.125rem;
    color: hsl(var(--secondary));
}

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

.number-card .number {
    font-size: 1.5rem;
    font-weight: 700;
    color: hsl(var(--primary));
    margin: var(--spacing-2) 0;
    letter-spacing: 0.05em;
}

/* Ad Slot Container (AdSense) */
.ad-slot {
    width: 100%;
    min-height: 90px;
    background-color: hsl(var(--bg-surface-hover));
    border: 1px dashed hsl(var(--border));
    display: flex;
    align-items: center;
    justify-content: center;
    color: hsl(var(--text-muted));
    font-size: 0.875rem;
    margin: var(--spacing-8) 0;
    border-radius: var(--radius-md);
}

/* Main Content Area */
.main-content {
    flex: 1;
}

/* SMS Table */
.sms-container {
    background-color: hsl(var(--bg-surface));
    border-radius: var(--radius-lg);
    border: 1px solid hsl(var(--border));
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.sms-header {
    background-color: hsl(var(--bg-surface-hover));
    padding: var(--spacing-4) var(--spacing-6);
    border-bottom: 1px solid hsl(var(--border));
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.sms-list {
    display: flex;
    flex-direction: column;
}

.sms-item {
    padding: var(--spacing-4) var(--spacing-6);
    border-bottom: 1px solid hsl(var(--border));
    display: grid;
    grid-template-columns: 150px 1fr 120px;
    gap: var(--spacing-4);
    align-items: center;
}

.sms-item:last-child {
    border-bottom: none;
}

.sms-item:hover {
    background-color: hsl(var(--bg-main));
}

.sms-sender {
    font-weight: 600;
    color: hsl(var(--secondary));
}

.sms-message {
    color: hsl(var(--text-main));
    word-break: break-word;
}

.sms-time {
    color: hsl(var(--text-muted));
    font-size: 0.875rem;
    text-align: right;
}

/* Number display big */
.number-display-big {
    font-size: 2.5rem;
    font-weight: 800;
    color: hsl(var(--primary));
    background: hsl(var(--bg-surface));
    padding: var(--spacing-4) var(--spacing-8);
    border-radius: var(--radius-lg);
    border: 2px dashed hsl(var(--primary), 0.3);
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-4);
    margin-bottom: var(--spacing-6);
    cursor: pointer;
    transition: all 0.2s;
}

.number-display-big:hover {
    background: hsl(var(--bg-main));
    border-color: hsl(var(--primary));
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: var(--spacing-8);
    right: var(--spacing-8);
    background-color: hsl(var(--secondary));
    color: white;
    padding: var(--spacing-3) var(--spacing-6);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    transform: translateY(150%);
    transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    z-index: 100;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.toast.show {
    transform: translateY(0);
}

/* Footer */
.footer {
    background-color: hsl(var(--secondary));
    color: white;
    padding: var(--spacing-12) 0 var(--spacing-6);
    margin-top: auto;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-8);
    margin-bottom: var(--spacing-8);
}

.footer h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-4);
    color: hsl(var(--bg-surface));
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2);
}

.footer-link {
    color: hsl(var(--text-muted));
    font-size: 0.875rem;
}

.footer-link:hover {
    color: white;
}

.footer-bottom {
    padding-top: var(--spacing-6);
    border-top: 1px solid hsl(var(--border), 0.1);
    text-align: center;
    color: hsl(var(--text-muted));
    font-size: 0.875rem;
}

/* Content Pages (FAQ, Privacy, Terms) */
.prose {
    max-width: 800px;
    margin: 0 auto;
    background: hsl(var(--bg-surface));
    padding: var(--spacing-8);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid hsl(var(--border));
}

.prose h1 {
    font-size: 2rem;
    color: hsl(var(--secondary));
    margin-bottom: var(--spacing-6);
    padding-bottom: var(--spacing-4);
    border-bottom: 1px solid hsl(var(--border));
}

.prose h2 {
    font-size: 1.5rem;
    color: hsl(var(--secondary));
    margin: var(--spacing-8) 0 var(--spacing-4);
}

.prose p {
    margin-bottom: var(--spacing-4);
    color: hsl(var(--text-main));
}

.prose ul {
    list-style: disc;
    padding-left: var(--spacing-6);
    margin-bottom: var(--spacing-4);
}

.prose li {
    margin-bottom: var(--spacing-2);
}

/* Responsive */
@media (max-width: 1024px) {
    .grid-cols-4 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .grid-cols-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .hero h1 { font-size: 2.25rem; }
    
    .nav-links {
        display: none;
        position: absolute;
        top: 4rem;
        left: 0;
        right: 0;
        background: hsl(var(--bg-surface));
        flex-direction: column;
        padding: var(--spacing-4);
        border-bottom: 1px solid hsl(var(--border));
        box-shadow: var(--shadow-md);
    }
    
    .nav-links.show {
        display: flex;
    }
    
    .mobile-menu-btn {
        display: block;
    }

    .sms-item {
        grid-template-columns: 1fr;
        gap: var(--spacing-2);
    }

    .sms-time {
        text-align: left;
    }
    
    .number-display-big {
        font-size: 1.5rem;
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .grid-cols-2 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
    .footer-grid { grid-template-columns: repeat(1, 1fr); }
}