/* ==========================================================================
   Main Stylesheet - Variables, Reset & Base Styles
   ========================================================================== */

/* CSS Variables */
:root {
    /* Colors - Light Mode (Default) */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-dark: #111827;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-primary: 'Poppins', sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 0.875rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Layout */
    --container-width: 1200px;
    --navbar-height: 70px;
    --border-radius: 8px;
    --border-radius-lg: 12px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-light: #9ca3af;
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-dark: #0f172a;
    --border-color: #374151;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
}

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

html {
    scroll-behavior: smooth;
    font-size: var(--font-size-base);
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-sm);
}

h1 { font-size: var(--font-size-5xl); }
h2 { font-size: var(--font-size-4xl); }
h3 { font-size: var(--font-size-3xl); }
h4 { font-size: var(--font-size-2xl); }
h5 { font-size: var(--font-size-xl); }
h6 { font-size: var(--font-size-lg); }

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

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

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

ul {
    list-style: none;
}

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

/* Section Styles */
.section {
    padding: var(--spacing-3xl) 0;
    position: relative;
}

.section:nth-child(even) {
    background-color: var(--bg-secondary);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section-title {
    font-size: var(--font-size-4xl);
    color: var(--text-primary);
    position: relative;
    display: inline-block;
    margin-bottom: var(--spacing-sm);
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
}

.section-subtitle {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-top: var(--spacing-md);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 32px;
    font-size: var(--font-size-base);
    font-weight: 500;
    border-radius: var(--border-radius);
    border: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition-base);
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #ffffff;
    border: 2px solid transparent;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover {
    background: var(--primary-color);
    color: #ffffff;
    transform: translateY(-2px);
}

/* Scroll to Top Button */
.scroll-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 60px;
    height: 60px;
    background: var(--bg-primary);
    color: var(--primary-color);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
    z-index: 999;
}

.scroll-top-content {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.scroll-top svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.scroll-top-circle-bg {
    fill: none;
    stroke: var(--border-color);
    stroke-width: 3;
}

.scroll-top-circle {
    fill: none;
    stroke: url(#scrollGradient);
    stroke-width: 3;
    stroke-linecap: round;
    transition: stroke-dashoffset 0.1s linear;
}

.scroll-top i {
    position: relative;
    z-index: 1;
}

.scroll-top:hover {
    transform: translateY(-5px) scale(1.05);
    box-shadow: var(--shadow-xl);
}

.scroll-top.show {
    display: flex;
}

/* Form Styles */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    font-size: var(--font-size-base);
    font-family: var(--font-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: all var(--transition-base);
    background-color: var(--bg-primary);
    color: var(--text-primary);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

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

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }

/* Loading Animation */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.6s ease-in-out;
}

/* Gradient Text */
.gradient-text {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}