/* ==========================================
   BUTTONS - Student Cycle
   Sky Blue Brand Colors | Fully Responsive
========================================== */

/* Base Button */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    border: 1px solid transparent;
    border-radius: var(--radius-md, 0.625rem);
    font-weight: 600;
    line-height: 1.2;
    text-align: center;
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    user-select: none;
    transition: all var(--transition-normal, 0.3s ease);
}

.btn:focus-visible {
    outline: 2px solid var(--color-primary-light, #7B93FF);
    outline-offset: 2px;
}

.btn:hover {
    text-decoration: none;
    transform: translateY(-1px);
}

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

/* ==========================================
   BUTTON SIZES - Responsive
========================================== */

/* Extra Small Devices (Phones < 576px) */
@media (max-width: 575.98px) {
    .btn-xs {
        min-height: 32px;
        padding: 6px 12px;
        font-size: 0.6875rem;
        border-radius: var(--radius-sm, 0.375rem);
    }

    .btn-sm {
        min-height: 38px;
        padding: 8px 16px;
        font-size: 0.75rem;
        border-radius: var(--radius-sm, 0.5rem);
    }

    .btn {
        min-height: 44px;
        padding: 10px 18px;
        font-size: 0.8125rem;
        border-radius: var(--radius-md, 0.5rem);
    }

    .btn-lg {
        min-height: 50px;
        padding: 12px 24px;
        font-size: 0.875rem;
        border-radius: var(--radius-md, 0.5625rem);
    }

    .btn-xl {
        min-height: 56px;
        padding: 14px 28px;
        font-size: 0.9375rem;
        border-radius: var(--radius-lg, 0.625rem);
    }
}

/* Small Devices (Phones 576px - 767px) */
@media (min-width: 576px) and (max-width: 767.98px) {
    .btn-xs {
        min-height: 34px;
        padding: 7px 14px;
        font-size: 0.6875rem;
        border-radius: var(--radius-sm, 0.375rem);
    }

    .btn-sm {
        min-height: 40px;
        padding: 9px 18px;
        font-size: 0.75rem;
        border-radius: var(--radius-sm, 0.5rem);
    }

    .btn {
        min-height: 46px;
        padding: 11px 20px;
        font-size: 0.8125rem;
        border-radius: var(--radius-md, 0.5rem);
    }

    .btn-lg {
        min-height: 52px;
        padding: 13px 26px;
        font-size: 0.875rem;
        border-radius: var(--radius-md, 0.5625rem);
    }

    .btn-xl {
        min-height: 58px;
        padding: 15px 30px;
        font-size: 0.9375rem;
        border-radius: var(--radius-lg, 0.625rem);
    }
}

/* Medium Devices (Tablets 768px - 991px) */
@media (min-width: 768px) and (max-width: 991.98px) {
    .btn-xs {
        min-height: 36px;
        padding: 8px 16px;
        font-size: 0.75rem;
        border-radius: var(--radius-sm, 0.375rem);
    }

    .btn-sm {
        min-height: 42px;
        padding: 10px 20px;
        font-size: 0.8125rem;
        border-radius: var(--radius-md, 0.5rem);
    }

    .btn {
        min-height: 48px;
        padding: 12px 22px;
        font-size: 0.875rem;
        border-radius: var(--radius-md, 0.5625rem);
    }

    .btn-lg {
        min-height: 54px;
        padding: 14px 28px;
        font-size: 0.9375rem;
        border-radius: var(--radius-lg, 0.625rem);
    }

    .btn-xl {
        min-height: 60px;
        padding: 16px 32px;
        font-size: 1rem;
        border-radius: var(--radius-lg, 0.6875rem);
    }
}

/* Large Devices (Desktops 992px - 1199px) */
@media (min-width: 992px) and (max-width: 1199.98px) {
    .btn-xs {
        min-height: 36px;
        padding: 8px 16px;
        font-size: 0.75rem;
        border-radius: var(--radius-sm, 0.375rem);
    }

    .btn-sm {
        min-height: 42px;
        padding: 10px 20px;
        font-size: 0.8125rem;
        border-radius: var(--radius-md, 0.5rem);
    }

    .btn {
        min-height: 48px;
        padding: 12px 24px;
        font-size: 0.875rem;
        border-radius: var(--radius-md, 0.5625rem);
    }

    .btn-lg {
        min-height: 56px;
        padding: 14px 30px;
        font-size: 0.9375rem;
        border-radius: var(--radius-lg, 0.625rem);
    }

    .btn-xl {
        min-height: 64px;
        padding: 16px 36px;
        font-size: 1rem;
        border-radius: var(--radius-lg, 0.6875rem);
    }
}

/* Extra Large Devices (Large Desktops 1200px - 1399px) */
@media (min-width: 1200px) and (max-width: 1399.98px) {
    .btn-xs {
        min-height: 38px;
        padding: 9px 18px;
        font-size: 0.75rem;
    }

    .btn-sm {
        min-height: 44px;
        padding: 11px 22px;
        font-size: 0.8125rem;
    }

    .btn {
        min-height: 50px;
        padding: 13px 26px;
        font-size: 0.875rem;
    }

    .btn-lg {
        min-height: 58px;
        padding: 15px 32px;
        font-size: 0.9375rem;
    }

    .btn-xl {
        min-height: 66px;
        padding: 17px 38px;
        font-size: 1rem;
    }
}

/* XXL Devices (4K Displays 1400px+) */
@media (min-width: 1400px) {
    .btn-xs {
        min-height: 40px;
        padding: 10px 20px;
        font-size: 0.8125rem;
        border-radius: var(--radius-md, 0.5rem);
    }

    .btn-sm {
        min-height: 46px;
        padding: 12px 24px;
        font-size: 0.875rem;
        border-radius: var(--radius-md, 0.5625rem);
    }

    .btn {
        min-height: 54px;
        padding: 14px 28px;
        font-size: 0.9375rem;
        border-radius: var(--radius-lg, 0.625rem);
    }

    .btn-lg {
        min-height: 62px;
        padding: 16px 34px;
        font-size: 1rem;
        border-radius: var(--radius-lg, 0.6875rem);
    }

    .btn-xl {
        min-height: 72px;
        padding: 18px 42px;
        font-size: 1.125rem;
        border-radius: var(--radius-xl, 0.75rem);
    }
}

/* ==========================================
   BUTTON VARIANTS
========================================== */

/* Primary Button - Sky Blue */
.btn-primary {
    background: linear-gradient(180deg, var(--color-primary-dark, #3B56D9) 0%, var(--color-primary, #4D6AFF) 100%);
    border-color: var(--color-primary, #4D6AFF);
    color: var(--color-white, #FFFFFF);
    box-shadow: 0 10px 24px rgba(77, 106, 255, 0.25);
}

.btn-primary:hover,
.btn-primary:focus {
    background: linear-gradient(180deg, var(--color-primary, #4D6AFF) 0%, var(--color-primary-light, #7B93FF) 100%);
    border-color: var(--color-primary-light, #7B93FF);
    color: var(--color-white, #FFFFFF);
    box-shadow: 0 14px 28px rgba(77, 106, 255, 0.35);
}

/* Outline Button */
.btn-outline {
    background: transparent;
    border: 1px solid var(--color-primary, #4D6AFF);
    color: var(--color-primary, #4D6AFF);
}

.btn-outline:hover,
.btn-outline:focus {
    background: var(--color-primary, #4D6AFF);
    border-color: var(--color-primary, #4D6AFF);
    color: var(--color-white, #FFFFFF);
    box-shadow: 0 12px 24px rgba(77, 106, 255, 0.2);
}

/* Outline Light (for dark backgrounds) */
.btn-outline-light {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.72);
    color: var(--color-white, #FFFFFF);
    backdrop-filter: blur(2px);
}

.btn-outline-light:hover,
.btn-outline-light:focus {
    background: var(--color-white, #FFFFFF);
    border-color: var(--color-white, #FFFFFF);
    color: var(--color-black, #111111);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.18);
}

/* Secondary Button - Cyan */
.btn-secondary {
    background: transparent;
    border: 1px solid var(--color-secondary, #00B4D8);
    color: var(--color-secondary, #00B4D8);
}

.btn-secondary:hover,
.btn-secondary:focus {
    background: var(--color-secondary, #00B4D8);
    border-color: var(--color-secondary, #00B4D8);
    color: var(--color-white, #FFFFFF);
    box-shadow: 0 12px 24px rgba(0, 180, 216, 0.25);
}

/* Danger/Delete Button */
.btn-danger {
    background: transparent;
    border: 1px solid var(--color-error, #EF4444);
    color: var(--color-error, #EF4444);
}

.btn-danger:hover,
.btn-danger:focus {
    background: var(--color-error, #EF4444);
    border-color: var(--color-error, #EF4444);
    color: var(--color-white, #FFFFFF);
    box-shadow: 0 12px 24px rgba(239, 68, 68, 0.25);
}

/* Success Button */
.btn-success {
    background: transparent;
    border: 1px solid var(--color-success, #10B981);
    color: var(--color-success, #10B981);
}

.btn-success:hover,
.btn-success:focus {
    background: var(--color-success, #10B981);
    border-color: var(--color-success, #10B981);
    color: var(--color-white, #FFFFFF);
    box-shadow: 0 12px 24px rgba(16, 185, 129, 0.25);
}

/* ==========================================
   BUTTON MODIFIERS
========================================== */

/* Full Width Button */
.btn-block {
    width: 100%;
    display: flex;
}

/* Rounded Button */
.btn-rounded {
    border-radius: var(--radius-full, 9999px);
}

/* Icon Only Button */
.btn-icon-only {
    padding: 0;
    width: 48px;
    height: 48px;
    border-radius: var(--radius-full, 9999px);
}

@media (max-width: 575.98px) {
    .btn-icon-only {
        width: 40px;
        height: 40px;
    }
}

/* Disabled State */
.btn:disabled,
.btn.disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
    pointer-events: none;
}

/* Loading State */
.btn-loading {
    position: relative;
    color: transparent !important;
    pointer-events: none;
}

.btn-loading::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    top: 50%;
    left: 50%;
    margin-left: -10px;
    margin-top: -10px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    .btn {
        transition: none;
    }
    .btn:hover,
    .btn:active {
        transform: none;
    }
    .btn-loading::after {
        animation: none;
    }
}

/* Button Group */
.btn-group {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: center;
}

.btn-group-vertical {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

@media (max-width: 575.98px) {
    .btn-group {
        flex-direction: column;
        width: 100%;
    }
    
    .btn-group .btn {
        width: 100%;
    }
}