/* ========================================
   AI Undetect - Modern Academic Rewriter
   ======================================== */

/* CSS Variables */
:root {
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);

    --bg-dark: #0f0f23;
    --bg-card: rgba(255, 255, 255, 0.03);
    --bg-card-hover: rgba(255, 255, 255, 0.06);

    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-muted: rgba(255, 255, 255, 0.5);

    --border-color: rgba(255, 255, 255, 0.1);
    --border-glow: rgba(102, 126, 234, 0.5);

    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 16px 64px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 40px rgba(102, 126, 234, 0.3);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 24px;

    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* Background Gradient Animation */
.background-gradient {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(ellipse at 20% 20%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(118, 75, 162, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(79, 172, 254, 0.08) 0%, transparent 60%);
    pointer-events: none;
    z-index: -1;
    animation: gradientPulse 15s ease-in-out infinite;
}

@keyframes gradientPulse {

    0%,
    100% {
        opacity: 1;
        transform: scale(1);
    }

    50% {
        opacity: 0.8;
        transform: scale(1.05);
    }
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 3rem;
    backdrop-filter: blur(20px);
    background: rgba(15, 15, 35, 0.8);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-icon {
    font-size: 1.8rem;
    animation: sparkle 2s ease-in-out infinite;
}

@keyframes sparkle {

    0%,
    100% {
        transform: scale(1) rotate(0deg);
    }

    50% {
        transform: scale(1.1) rotate(10deg);
    }
}

.logo-text {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-gradient);
    transition: width var(--transition-normal);
}

.nav-link:hover {
    color: var(--text-primary);
}

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

/* Main Container */
.main-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem 3rem 4rem;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 3rem 0 4rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.gradient-text {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Editor Section */
.editor-section {
    margin-bottom: 5rem;
}

.editor-container {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 1.5rem;
    align-items: stretch;
}

.editor-panel {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    min-height: 500px;
    transition: all var(--transition-normal);
}

.editor-panel:hover {
    border-color: var(--border-glow);
    box-shadow: var(--shadow-glow);
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    background: rgba(255, 255, 255, 0.02);
    border-bottom: 1px solid var(--border-color);
}

.panel-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 1rem;
}

.panel-icon {
    font-size: 1.2rem;
}

.char-count {
    font-size: 0.875rem;
    color: var(--text-muted);
    background: rgba(255, 255, 255, 0.05);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
}

.editor-textarea {
    flex: 1;
    width: 100%;
    padding: 1.5rem;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    line-height: 1.8;
    resize: none;
    outline: none;
}

.editor-textarea::placeholder {
    color: var(--text-muted);
}

.editor-output {
    flex: 1;
    padding: 1.5rem;
    font-size: 1rem;
    line-height: 1.8;
    overflow-y: auto;
    white-space: pre-wrap;
    word-wrap: break-word;
}

.placeholder-text {
    color: var(--text-muted);
    font-style: italic;
}

/* Control Panel */
.control-panel {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    padding: 0 1rem;
}

/* Text Type Selector */
.text-type-selector {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.selector-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.type-select {
    padding: 0.75rem 1.25rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    min-width: 180px;
    text-align: center;
}

.type-select:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--border-glow);
}

.type-select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
}

.type-select option {
    background: var(--bg-dark);
    color: var(--text-primary);
    padding: 0.5rem;
}

.rewrite-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1.5rem 2rem;
    background: var(--primary-gradient);
    border: none;
    border-radius: var(--radius-lg);
    color: white;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-md);
}

.rewrite-btn:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

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

.rewrite-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-icon {
    font-size: 1.5rem;
}

.loading-indicator {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.loading-indicator.active {
    display: flex;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top-color: #667eea;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: 0.5rem;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.action-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border-color: var(--border-glow);
}

/* Features Section */
.features-section {
    margin-bottom: 5rem;
}

.section-title {
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 3rem;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem;
    text-align: center;
    transition: all var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--border-glow);
    box-shadow: var(--shadow-glow);
    background: var(--bg-card-hover);
}

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

.feature-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.feature-card p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* How It Works Section */
.how-section {
    margin-bottom: 3rem;
}

.steps-container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.step {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem 2rem;
    transition: all var(--transition-normal);
}

.step:hover {
    border-color: var(--border-glow);
    box-shadow: var(--shadow-glow);
}

.step-number {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-gradient);
    border-radius: 50%;
    font-size: 1.25rem;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.step-content p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.step-arrow {
    font-size: 1.5rem;
    color: var(--text-muted);
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
    font-size: 0.875rem;
    border-top: 1px solid var(--border-color);
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--primary-gradient);
    color: white;
    padding: 1rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transition: all var(--transition-normal);
    z-index: 1000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 992px) {
    .editor-container {
        grid-template-columns: 1fr;
    }

    .control-panel {
        flex-direction: row;
        padding: 1rem 0;
    }

    .steps-container {
        flex-direction: column;
    }

    .step-arrow {
        transform: rotate(90deg);
    }
}

@media (max-width: 768px) {
    .header {
        padding: 1rem 1.5rem;
    }

    .nav {
        display: none;
    }

    .main-container {
        padding: 1rem 1.5rem 3rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

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

    .editor-panel {
        min-height: 300px;
    }
}