:root {
    --zoo-50: #f0fdf4;
    --zoo-100: #dcfce7;
    --zoo-200: #bbf7d0;
    --zoo-300: #86efac;
    --zoo-400: #4ade80;
    --zoo-500: #22c55e;
    --zoo-600: #16a34a;
    --zoo-700: #15803d;
    --zoo-800: #166534;
    --zoo-900: #14532d;
    --zoo-950: #052e16;
}

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

html {
    scroll-behavior: smooth;
}

html, body {
    overflow-x: hidden;
    max-width: 100vw;
}

body {
    font-family: 'Open Sans', sans-serif;
    background-color: var(--zoo-50);
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Montserrat', sans-serif;
}

/* Hero Section */
.hero-bg {
    background: linear-gradient(135deg, #052e16 0%, #14532d 25%, #166534 50%, #15803d 75%, #16a34a 100%);
    animation: heroGradient 15s ease infinite;
}

@keyframes heroGradient {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.hero-section {
    background: linear-gradient(135deg, rgba(5, 46, 22, 0.9), rgba(20, 83, 45, 0.85));
}

/* Navbar */
#navbar {
    transition: all 0.3s ease;
}

#navbar.scrolled {
    background: rgba(20, 83, 45, 0.95);
    backdrop-filter: blur(20px);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.15);
}

/* Hamburger Menu */
.hamburger {
    display: flex;
    flex-direction: column;
    gap: 5px;
    width: 24px;
}

.hamburger span {
    display: block;
    width: 100%;
    height: 2px;
    background: white;
    transition: all 0.3s ease;
    border-radius: 2px;
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* Species Tabs */
.species-tab {
    background: white;
    color: #374151;
    border: 1px solid #e5e7eb;
}

.species-tab:hover {
    background: var(--zoo-100);
    border-color: var(--zoo-300);
    color: var(--zoo-700);
}

.species-tab.active {
    background: var(--zoo-500);
    color: white;
    border-color: var(--zoo-500);
    box-shadow: 0 4px 15px rgba(34, 197, 94, 0.3);
}

/* Upload Zone */
.upload-zone {
    transition: all 0.3s ease;
}

.upload-zone:hover {
    border-color: var(--zoo-500);
    background: rgba(220, 252, 231, 0.5);
}

.upload-zone.dragover {
    border-color: var(--zoo-500);
    background: rgba(220, 252, 231, 0.8);
    transform: scale(1.02);
}

/* File Preview */
.file-preview-item {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    aspect-ratio: 1;
    background: #f3f4f6;
}

.file-preview-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.file-preview-item .remove-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    width: 28px;
    height: 28px;
    background: rgba(239, 68, 68, 0.9);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    transition: all 0.2s ease;
}

.file-preview-item .remove-btn:hover {
    background: #dc2626;
    transform: scale(1.1);
}

/* Counter Animation */
.counter {
    transition: all 0.3s ease;
}

/* Species Card */
.species-card {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.species-card:hover {
    transform: translateY(-4px);
}

.species-badge {
    font-size: 10px;
    line-height: 1;
    padding: 3px 8px;
}

/* Footer Wave */
.footer-wave {
    margin-top: -1px;
}

.footer-wave svg {
    display: block;
    width: 100%;
    height: 60px;
}

/* Animations */
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--zoo-100);
}

::-webkit-scrollbar-thumb {
    background: var(--zoo-500);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--zoo-600);
}

/* Selection */
::selection {
    background: var(--zoo-200);
    color: var(--zoo-900);
}

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

/* Active Nav Link */
.nav-link {
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--zoo-400);
    transition: width 0.3s ease;
    border-radius: 1px;
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 60%;
}

/* Species Category */
.species-category {
    padding: 20px 0;
    border-bottom: 1px solid #f3f4f6;
}

.species-category:last-child {
    border-bottom: none;
}