/* css/style.css */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');
@import url('https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.0.0-beta3/css/all.min.css');

/* CSS Variables for theming */
:root {
    --background: #f9fafb;
    --surface: #ffffff;
    --primary-text: #111827;
    --secondary-text: #4b5563;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --border-color: #e5e7eb;
    --shadow-color: rgba(0, 0, 0, 0.05);
    --header-bg: rgba(255, 255, 255, 0.8);
}

html.theme-dark {
    --background: #111827;
    --surface: #1f2937;
    --primary-text: #e5e7eb;
    --secondary-text: #9ca3af;
    --border-color: #374151;
    --shadow-color: rgba(0, 0, 0, 0.2);
    --header-bg: rgba(17, 24, 39, 0.8);
}

body {
    font-family: 'Inter', sans-serif;
    scroll-behavior: smooth;
    background-color: var(--background);
    color: var(--primary-text);
    transition: background-color 0.3s ease, color 0.3s ease;
}

header {
    background-color: var(--header-bg);
    box-shadow: 0 4px 6px -1px var(--shadow-color);
}
.bg-surface { background-color: var(--surface); }
.text-primary { color: var(--primary-text); }
.text-secondary { color: var(--secondary-text); }
.text-accent { color: var(--accent); }
.border-custom { border-color: var(--border-color); }

.card-hover, .bg-surface, .text-primary, .text-secondary, .filter-btn, .btn-primary, .btn-secondary {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, transform 0.3s ease;
}

.btn-primary {
    display: inline-block;
    text-align: center;
    background-color: var(--accent);
    color: white;
    font-weight: bold;
    cursor: pointer;
}
.btn-primary:hover {
    background-color: var(--accent-hover);
}

.btn-secondary {
    display: inline-block;
    text-align: center;
    background-color: transparent;
    color: var(--accent);
    border: 2px solid var(--accent);
    font-weight: bold;
    cursor: pointer;
}
.btn-secondary:hover {
    background-color: var(--accent);
    color: white;
}

/* --- NAVIGATION MENU (Underline Animation + Bold Active) --- */
.nav-link {
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    font-weight: 500;
    color: var(--secondary-text);
    padding-bottom: 4px;
    position: relative;
    transition: color 0.3s ease;
    text-decoration: none;
}

/* The Underline (Hidden by default) */
.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--accent);
    transition: width 0.3s ease;
}

/* Hover State */
.nav-link:hover {
    color: var(--accent); /* Changed to accent for better visibility */
}
.nav-link:hover::after {
    width: 100%;
}

/* Active State (Current Page) */
.nav-link.active {
    color: var(--primary-text);
    font-weight: 700; /* BOLD as requested */
}

/* Keep the underline fixed for the active page */
.nav-link.active::after {
    width: 100%;
}

.hero-gradient {
    background: linear-gradient(135deg, var(--background) 0%, var(--surface) 100%);
}
html.theme-dark .hero-gradient {
     background: linear-gradient(135deg, #111827 0%, #1f2937 100%);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--primary-text);
}
.section-subtitle {
    font-size: 1.125rem;
    color: var(--secondary-text);
    max-width: 600px;
    margin: 0 auto 3rem auto;
}

.card-hover:hover {
    transform: translateY(-8px);
    box-shadow: 0 10px 20px var(--shadow-color);
}

.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}
.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* UPDATED: Filter Buttons (Pill Style) */
.filter-btn {
    background-color: var(--surface);
    color: var(--secondary-text);
    border: 1px solid var(--border-color);
    border-radius: 9999px; /* This makes it a Pill */
    padding: 0.6rem 1.8rem; /* Wider padding for better look */
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn:hover {
    background-color: var(--border-color);
    color: var(--primary-text);
    transform: translateY(-2px); /* Slight lift effect */
}

.filter-btn.active {
    background-color: var(--accent);
    color: white;
    border-color: var(--accent);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3); /* Glow effect */
}
/* Mobile Dropdown Styling */
.mobile-filter-select {
    background-color: var(--surface);
    color: var(--primary-text);
    border: 1px solid var(--border-color);
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 0.5rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
    padding-right: 2.5rem;
}
/* Theme Toggle */
#theme-toggle {
    position: relative;
    width: 56px;
    height: 32px;
    border: none;
    background: none;
    padding: 0;
    cursor: pointer;
}
.toggle-track {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: #dbeafe;
    border-radius: 30px;
    transition: background-color 0.4s;
}
.toggle-thumb {
    position: absolute;
    height: 24px; width: 24px;
    border-radius: 50%;
    left: 4px; bottom: 4px;
    background-color: #f59e0b;
    transition: all 0.4s cubic-bezier(0.68, -0.55, 0.27, 1.55);
    box-shadow: 0 0 5px #f59e0b;
}
html.theme-dark .toggle-track { background-color: #374151; }
html.theme-dark .toggle-thumb {
    transform: translateX(24px);
    background-color: #e5e7eb;
    box-shadow: inset -3px -2px 5px -2px rgba(255,255,255,0.2), inset -8px -3px 0 0 #dbeafe;
}