:root {
    --primary: #0a0e27;
    --secondary: #1a1f3a;
    --accent: #4a9eff;
    --accent-dark: #2d7dd2;
    --text: #e8eaf6;
    --text-dim: #9ca3c3;
    --border: #2a3150;
    --success: #4caf50;
    --warning: #ff9800;
    --error: #f44336;
    --card-bg: #151937;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'DM Sans', sans-serif;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header Styles */
header {
    background: rgba(10, 14, 39, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 0;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    font-family: 'JetBrains Mono', monospace;
    color: var(--accent);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo::before {
    content: '⚡';
    font-size: 2rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s ease;
}

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

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

/* Hero Section */
.hero {
    text-align: center;
    padding: 4rem 0;
    animation: fadeIn 0.8s ease-out;
}

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

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--accent) 0%, #7ec8ff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

.hero p {
    font-size: 1.3rem;
    color: var(--text-dim);
    max-width: 600px;
    margin: 0 auto 2rem;
}

/* Category Section */
.category-section {
    padding: 3rem 0;
}

.category-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.category-header h2 {
    font-size: 2rem;
    color: var(--accent);
    font-family: 'JetBrains Mono', monospace;
}

.category-header::after {
    content: '';
    flex: 1;
    height: 2px;
    background: linear-gradient(90deg, var(--accent) 0%, transparent 100%);
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    animation: slideUp 0.6s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tool-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2rem;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    display: block;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--accent), #7ec8ff);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.tool-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent);
    box-shadow: 0 10px 30px rgba(74, 158, 255, 0.2);
}

.tool-card:hover::before {
    transform: scaleX(1);
}

.tool-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.tool-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.tool-card p {
    color: var(--text-dim);
    font-size: 0.95rem;
}

/* Page Styles */
.page-container {
    padding: 3rem 0;
    animation: fadeIn 0.5s ease-out;
}

.page-header {
    text-align: center;
    margin-bottom: 3rem;
}

.page-header h1 {
    font-size: 2.5rem;
    color: var(--accent);
    margin-bottom: 1rem;
}

.breadcrumb {
    color: var(--text-dim);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.breadcrumb a {
    color: var(--accent);
    text-decoration: none;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

/* Calculator Container */
.calculator-container {
    max-width: 600px;
    margin: 0 auto;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 2.5rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.display {
    background: var(--secondary);
    border: 2px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 2rem;
    text-align: right;
    min-height: 80px;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    word-break: break-all;
}

.display-history {
    font-size: 1rem;
    color: var(--text-dim);
    margin-bottom: 0.5rem;
}

.button-grid {
    display: grid;
    gap: 0.75rem;
}

.btn {
    padding: 1.2rem;
    font-size: 1.2rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.2s ease;
    font-family: 'JetBrains Mono', monospace;
}

.btn:hover {
    transform: scale(1.05);
}

.btn:active {
    transform: scale(0.98);
}

.btn-number {
    background: var(--secondary);
    color: var(--text);
    border: 1px solid var(--border);
}

.btn-number:hover {
    background: #252b4a;
}

.btn-operator {
    background: var(--accent);
    color: white;
}

.btn-operator:hover {
    background: var(--accent-dark);
}

.btn-clear {
    background: var(--error);
    color: white;
}

.btn-equals {
    background: var(--success);
    color: white;
}

/* Form Styles */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text);
    font-weight: 500;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 0.875rem;
    background: var(--secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-size: 1rem;
    font-family: 'DM Sans', sans-serif;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--accent);
}

.result-box {
    background: var(--secondary);
    border: 2px solid var(--accent);
    border-radius: 8px;
    padding: 1.5rem;
    margin-top: 1.5rem;
    text-align: center;
    animation: slideUp 0.3s ease-out;
}

.result-box h3 {
    color: var(--accent);
    margin-bottom: 0.5rem;
}

.result-box .value {
    font-size: 2rem;
    font-weight: 700;
    font-family: 'JetBrains Mono', monospace;
    color: var(--success);
}

/* Contact Page */
.contact-container {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-container h1 {
    font-size: 2.5rem;
    color: var(--accent);
    margin-bottom: 2rem;
}

.email-box {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 3rem;
    margin: 2rem 0;
}

.email-box .icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.email-box a {
    color: var(--accent);
    font-size: 1.5rem;
    text-decoration: none;
    font-weight: 600;
    font-family: 'JetBrains Mono', monospace;
}

.email-box a:hover {
    color: #7ec8ff;
}

/* Footer */
footer {
    background: rgba(10, 14, 39, 0.95);
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    text-align: center;
    margin-top: 4rem;
}

footer p {
    color: var(--text-dim);
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }

    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
    }

    .tools-grid {
        grid-template-columns: 1fr;
    }

    .calculator-container {
        padding: 1.5rem;
    }

    .page-header h1 {
        font-size: 2rem;
    }
}