:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --secondary-color: #6b7280;
    --background: #f9fafb;
    --surface: #ffffff;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --success-bg: #d1fae5;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 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);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 2rem 1rem;
    width: 100%;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

.logo-title {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.logo {
    width: 48px;
    height: 56px;
    filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.2)) drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
}

header p {
    color: var(--text-secondary);
    font-size: 1.425rem;
}

main {
    background: var(--surface);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-row {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 1rem;
}

/* When all-day is checked: 2 equal columns for dates */
.form-row.all-day-mode {
    grid-template-columns: 1fr 1fr;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-size: 0.9rem;
}

input[type="text"],
input[type="date"],
input[type="time"],
input[type="number"],
select,
textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 0.95rem;
    font-family: inherit;
    transition: all 0.2s;
    background: var(--surface);
}

input[type="text"]:focus,
input[type="date"]:focus,
input[type="time"]:focus,
input[type="number"]:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%236b7280' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    padding-right: 2.5rem;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    font-weight: 600;
    user-select: none;
}

input[type="checkbox"] {
    width: 1.25rem;
    height: 1.25rem;
    cursor: pointer;
    accent-color: var(--primary-color);
}

.checkbox-label span {
    font-size: 0.95rem;
}

.help-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
    font-style: italic;
}

.weekday-buttons {
    display: flex;
    gap: 0.5rem;
    margin-top: 0.5rem;
    flex-wrap: wrap;
}

.weekday-btn {
    position: relative;
    cursor: pointer;
    user-select: none;
}

.weekday-btn input[type="checkbox"] {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.weekday-btn span {
    display: inline-block;
    padding: 0.5rem 0.75rem;
    background: var(--background);
    border: 2px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.2s;
    min-width: 45px;
    text-align: center;
}

.weekday-btn input[type="checkbox"]:checked + span {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.weekday-btn:hover span {
    border-color: var(--primary-color);
}

textarea {
    resize: vertical;
    min-height: 100px;
}

.form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.btn {
    flex: 1;
    padding: 0.875rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--background);
    color: var(--text-secondary);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--border-color);
}

.success-message {
    margin-top: 1.5rem;
    padding: 1rem 1.5rem;
    background: var(--success-bg);
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    animation: slideIn 0.3s ease-out;
}

.success-icon {
    font-size: 1.5rem;
    color: var(--success-color);
}

#successText {
    color: var(--success-color);
    font-weight: 600;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

footer {
    text-align: center;
    margin-top: 2rem;
    padding: 1rem;
    color: var(--text-secondary);
    font-size: 1.275rem;
}

/* Responsive */
@media (max-width: 640px) {
    .form-row {
        grid-template-columns: 1fr;
    }

    .form-actions {
        flex-direction: column;
    }

    header h1 {
        font-size: 1.5rem;
    }

    main {
        padding: 1.5rem;
    }
}

/* Custom date/time input styling */
input[type="date"],
input[type="time"] {
    cursor: pointer;
}

input[type="date"]::-webkit-calendar-picker-indicator,
input[type="time"]::-webkit-calendar-picker-indicator {
    cursor: pointer;
    filter: opacity(0.5);
}

input[type="date"]::-webkit-calendar-picker-indicator:hover,
input[type="time"]::-webkit-calendar-picker-indicator:hover {
    filter: opacity(1);
}