/* Core Variables & Reset */
:root {
    --bg-color: #F8FAFC;
    --primary-color: #2563EB;
    --primary-hover: #1D4ED8;
    --text-main: #0F172A;
    --text-muted: #64748B;
    --card-bg: #FFFFFF;
    --border-color: #E2E8F0;
    --success-bg: #DCFCE7;
    --success-text: #166534;
    --error-bg: #FEE2E2;
    --error-text: #991B1B;
    
    --radius-lg: 18px;
    --radius-md: 12px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
    
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 5%;
    background-color: var(--card-bg);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.nav a {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    transition: var(--transition);
}

.nav a:hover, .nav a.active {
    color: var(--primary-color);
}

.header-right {
    display: flex;
    gap: 1.5rem;
}

.header-right a {
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    transition: var(--transition);
}

.header-right a:hover {
    color: var(--primary-color);
}

/* Main Layout */
.main-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 3rem 1rem;
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
}

.card {
    background-color: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: 2.5rem;
    width: 100%;
    transition: var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-title {
    font-size: 1.85rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    text-align: center;
    letter-spacing: -0.02em;
}

.card-subtitle {
    color: var(--text-muted);
    text-align: center;
    margin-bottom: 2rem;
    font-size: 1.05rem;
}

/* Input Area */
.input-group {
    margin-bottom: 1.5rem;
}

textarea {
    width: 100%;
    padding: 1.25rem;
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 1.1rem;
    color: var(--text-main);
    resize: vertical;
    outline: none;
    transition: var(--transition);
    background-color: #F8FAFC;
}

textarea:focus {
    border-color: var(--primary-color);
    background-color: var(--card-bg);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

/* Buttons */
.button-group {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    box-shadow: 0 4px 6px rgba(37, 99, 235, 0.2);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
    background-color: #F1F5F9;
    color: var(--text-main);
}

.btn-secondary:hover {
    background-color: #E2E8F0;
    transform: translateY(-2px);
}

/* Result Section */
.result-section {
    padding: 2rem;
    overflow: hidden;
}

.result-section.hidden {
    display: none;
    opacity: 0;
}

.result-section.fade-in {
    display: block;
    animation: fadeIn 0.5s forwards;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

.result-card {
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    border: 2px solid transparent;
    transition: var(--transition);
}

.result-card.success {
    background-color: var(--success-bg);
    border-color: #BBF7D0;
}

.result-card.error {
    background-color: var(--error-bg);
    border-color: #FECACA;
}

.result-icon-container {
    font-size: 3.5rem;
    margin-bottom: 0.5rem;
}

.success .result-icon-container { color: var(--success-text); }
.error .result-icon-container { color: var(--error-text); }

.result-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

.success .result-title { color: var(--success-text); }
.error .result-title { color: var(--error-text); }

.stats-container {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    background-color: rgba(255, 255, 255, 0.7);
    padding: 1.75rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.stat-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.stat-value {
    font-size: 1.15rem;
    word-break: break-all;
    font-weight: 500;
    color: var(--text-main);
}

/* Footer */
.footer {
    text-align: center;
    padding: 2.5rem 1rem;
    color: var(--text-muted);
    background-color: var(--card-bg);
    border-top: 1px solid var(--border-color);
    margin-top: auto;
}

.footer-links {
    margin-top: 0.75rem;
    font-size: 0.95rem;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
}

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-color);
}

.separator {
    color: var(--border-color);
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.toast {
    background-color: var(--card-bg);
    color: var(--text-main);
    padding: 1rem 1.5rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transform: translateX(120%);
    transition: transform 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    border-left: 4px solid var(--primary-color);
    font-weight: 500;
}

.toast.show {
    transform: translateX(0);
}

.toast.success { border-left-color: #10B981; }
.toast.info { border-left-color: var(--primary-color); }
.toast.error { border-left-color: #EF4444; }