/* Premium Design System & Color Tokens */
:root {
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --border-color: #e2e8f0;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --accent-glow: rgba(37, 99, 235, 0.15);
    
    --success-bg: #f0fdf4;
    --success-border: #bbf7d0;
    --success-text: #15803d;
    
    --error-bg: #fef2f2;
    --error-border: #fecaca;
    --error-text: #b91c1c;

    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.03);
    --radius: 16px;
    --radius-sm: 8px;
}

body.dark-mode {
    --bg-color: #0b0f19;
    --card-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --accent: #38bdf8;
    --accent-hover: #0ea5e9;
    --accent-glow: rgba(14, 165, 233, 0.15);
    
    --success-bg: #052e16;
    --success-border: #14532d;
    --success-text: #4ade80;
    
    --error-bg: #451a1a;
    --error-border: #7f1d1d;
    --error-text: #fca5a5;

    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
}

/* Global resets and structure */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    transition: background-color 0.3s cubic-bezier(0.4, 0, 0.2, 1), color 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow-x: hidden;
}

/* Base gradients and dynamic decorations */
body::before {
    content: '';
    position: absolute;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
    top: -50px;
    left: -50px;
    z-index: 0;
    pointer-events: none;
}

body::after {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
    bottom: -100px;
    right: -100px;
    z-index: 0;
    pointer-events: none;
}

.container {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 40px 32px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 520px;
    position: relative;
    z-index: 1;
    transition: background-color 0.3s, border-color 0.3s;
    backdrop-filter: blur(8px);
}

/* Branding elements */
.brand {
    text-align: center;
    margin-bottom: 32px;
}

.brand-icon {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    width: 64px;
    height: 64px;
    border-radius: 16px;
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-hover) 100%);
    color: #ffffff;
    margin-bottom: 18px;
    box-shadow: 0 8px 20px var(--accent-glow);
}

h1 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
    letter-spacing: -0.025em;
}

.brand p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Form Styles */
#shorten-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.link-icon {
    position: absolute;
    left: 16px;
    color: var(--text-secondary);
    pointer-events: none;
    transition: color 0.3s;
}

input[type="url"], input[type="text"] {
    width: 100%;
    padding: 14px 16px 14px 48px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 14px;
    background-color: var(--bg-color);
    color: var(--text-primary);
    transition: all 0.2s ease-in-out;
    outline: none;
}

input[type="url"]:focus, input[type="text"]:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 4px var(--accent-glow);
    background-color: var(--card-bg);
}

button[type="submit"] {
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-hover) 100%);
    color: #ffffff;
    border: none;
    padding: 14px 24px;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    box-shadow: 0 4px 12px var(--accent-glow);
}

button[type="submit"]:hover:not(:disabled) {
    transform: translateY(-1px);
    box-shadow: 0 6px 18px var(--accent-glow);
}

button[type="submit"]:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

/* Result & Messages */
.result-box {
    margin-top: 24px;
    padding: 20px;
    border-radius: var(--radius-sm);
    display: flex;
    flex-direction: column;
    gap: 12px;
    border: 1px solid transparent;
    animation: fadeIn 0.3s ease-out;
}

.result-box p {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
}

.result-box.success {
    background-color: var(--success-bg);
    border-color: var(--success-border);
}

.result-box.success p {
    color: var(--success-text);
}

.icon-success-wrapper {
    color: var(--success-text);
}

.result-box.error {
    background-color: var(--error-bg);
    border-color: var(--error-border);
}

.result-box.error p {
    color: var(--error-text);
}

.icon-error-wrapper {
    color: var(--error-text);
}

.output-group {
    display: flex;
    gap: 10px;
}

.output-group input {
    padding: 12px 14px;
    font-family: monospace;
    font-size: 13px;
    background-color: var(--card-bg);
}

.output-group button {
    background-color: var(--text-primary);
    color: var(--card-bg);
    border: none;
    border-radius: var(--radius-sm);
    padding: 0 16px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;
    white-space: nowrap;
}

.output-group button:hover {
    opacity: 0.9;
}

.hidden {
    display: none;
}

/* Custom redirection and countdown design */
.redirect-page {
    text-align: center;
}

.ad-banner {
    margin-bottom: 24px;
    overflow: hidden;
    border-radius: var(--radius-sm);
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    border: 1px solid var(--border-color);
}

.ad-banner img {
    max-width: 100%;
    height: auto;
    display: block;
    transition: transform 0.3s ease;
}

.ad-banner img:hover {
    transform: scale(1.02);
}

.destination-link {
    background-color: var(--bg-color);
    color: var(--text-secondary);
    padding: 14px 16px;
    border-radius: var(--radius-sm);
    font-family: monospace;
    word-wrap: break-word;
    margin-bottom: 24px;
    font-size: 14px;
    border: 1px solid var(--border-color);
}

#countdown-timer {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 24px;
    color: #e11d48;
}

#seconds {
    font-weight: 700;
}

.btn-redirect {
    display: block;
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-hover) 100%);
    color: #ffffff;
    padding: 14px;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 600;
    text-decoration: none;
    box-shadow: 0 4px 12px var(--accent-glow);
    transition: all 0.2s;
}

.btn-redirect.disabled {
    background: #cbd5e1;
    color: #64748b;
    box-shadow: none;
    pointer-events: none;
    cursor: not-allowed;
}

body.dark-mode .btn-redirect.disabled {
    background: #334155;
    color: #64748b;
}

/* Spinner */
.spinner {
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--accent);
    border-radius: 50%;
    width: 24px;
    height: 24px;
    animation: spin 1s linear infinite;
    align-self: center;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Theme toggle switches */
.theme-switch-wrapper {
    display: flex;
    align-items: center;
    position: absolute;
    top: 24px;
    right: 24px;
    gap: 10px;
    z-index: 10;
}

.theme-switch-wrapper span {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
}

.theme-switch {
    display: inline-block;
    height: 24px;
    position: relative;
    width: 44px;
}

.theme-switch input {
    display: none;
}

.slider {
    background-color: #cbd5e1;
    bottom: 0;
    cursor: pointer;
    left: 0;
    position: absolute;
    right: 0;
    top: 0;
    transition: .3s;
}

.slider:before {
    background-color: #ffffff;
    bottom: 4px;
    content: "";
    height: 16px;
    left: 4px;
    position: absolute;
    transition: .3s;
    width: 16px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

input:checked + .slider {
    background-color: var(--accent);
}

input:checked + .slider:before {
    transform: translateX(20px);
}

.slider.round {
    border-radius: 24px;
}

.slider.round:before {
    border-radius: 50%;
}