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

:root {
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #262626;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --accent: #4a9eff;
    --accent-hover: #6bb0ff;
    --error: #ff4444;
    --success: #44ff44;
    --border: #333333;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid var(--border);
}

h1 {
    font-size: 3rem;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 0.5rem;
    font-family: monospace;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.input-section {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 2rem;
    border: 1px solid var(--border);
    max-width: 100%;
}

label {
    display: block;
    margin-bottom: 0.75rem;
    font-weight: 500;
    color: var(--text-primary);
}

.input-group {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

input[type="text"] {
    flex: 1;
    padding: 0.75rem 1rem;
    background: var(--bg-tertiary);
    border: 2px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    font-family: monospace;
    transition: border-color 0.2s;
}

input[type="text"]:focus {
    outline: none;
    border-color: var(--accent);
}

input[type="text"]::placeholder {
    color: var(--text-secondary);
}

button {
    padding: 0.75rem 1.5rem;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
}

button:hover {
    background: var(--accent-hover);
}

button:active {
    transform: scale(0.98);
}

#clear-btn {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 2px solid var(--border);
}

#clear-btn:hover {
    background: var(--border);
}

#now-btn {
    width: 100%;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 2px solid var(--border);
}

#now-btn:hover {
    background: var(--border);
}

.loading {
    text-align: center;
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: 12px;
    border: 1px solid var(--border);
}

.spinner {
    width: 40px;
    height: 40px;
    margin: 0 auto 1rem;
    border: 4px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.error {
    padding: 1rem 1.5rem;
    background: rgba(255, 68, 68, 0.1);
    border: 2px solid var(--error);
    border-radius: 8px;
    color: var(--error);
    margin-bottom: 1rem;
}

.hidden {
    display: none;
}

.results {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    align-items: start;
}

@media (min-width: 1100px) {
    .results {
        grid-template-columns: repeat(2, 1fr);
        grid-auto-rows: auto;
    }

    /* Explicit grid placement for horizontal alignment */
    .result-section:nth-child(1) { grid-column: 1; grid-row: 1; } /* Input */
    .result-section:nth-child(2) { grid-column: 1; grid-row: 2; } /* UTC */
    .result-section:nth-child(3) { grid-column: 2; grid-row: 1; } /* Local Time */
    .result-section:nth-child(4) { grid-column: 2; grid-row: 2; } /* Relative */
}

.result-section {
    background: var(--bg-secondary);
    padding: 1.5rem 1.5rem 1rem;
    border-radius: 12px;
    border: 1px solid var(--border);
    height: fit-content;
}

.result-section h2 {
    font-size: 1.5rem;
    color: var(--accent);
    margin-bottom: 1rem;
    font-weight: 600;
}

.result-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border);
}

.result-item:last-child {
    border-bottom: none;
}

.result-item .label {
    color: var(--text-secondary);
    font-weight: 500;
    min-width: 150px;
    font-size: 1.05rem;
}

.result-item .value {
    color: var(--text-primary);
    font-family: monospace;
    font-weight: 600;
    text-align: right;
    word-break: break-all;
    font-size: 1.1rem;
    flex: 1;
}

.copy-btn {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    padding: 0.5rem;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    flex-shrink: 0;
}

.copy-btn:hover {
    background: var(--bg-tertiary);
    color: var(--accent);
    border-color: var(--accent);
}

.copy-btn:active {
    transform: scale(0.95);
}

.copy-btn.copied {
    color: var(--success);
    border-color: var(--success);
}

.copy-btn svg {
    display: block;
}

.verify-text {
    margin-top: 0.5rem;
    margin-bottom: 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-style: italic;
}

footer {
    text-align: center;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    color: var(--text-secondary);
}

footer a {
    color: var(--accent);
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }

    .input-group {
        flex-direction: column;
    }

    .result-item {
        flex-wrap: wrap;
    }

    .result-item .label {
        min-width: auto;
        flex-basis: 100%;
    }

    .result-item .value {
        text-align: left;
    }

    .copy-btn {
        margin-left: auto;
    }
}