/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 0.75rem 1.75rem; font-size: 0.875rem; font-weight: 500;
    border-radius: var(--radius-md); cursor: pointer;
    transition: all var(--transition-base);
    gap: 0.5rem; position: relative; overflow: hidden;
    isolation: isolate; border: 1px solid transparent;
    white-space: nowrap; user-select: none;
}

/* ── Primary ── */
.btn-primary {
    background: var(--text-main); color: var(--bg-main);
}

.btn-primary:hover {
    background: transparent; color: var(--text-main);
    border-color: var(--border-light);
    box-shadow: var(--shadow-glow);
    transform: translateY(-2px);
}

.btn-primary:active { transform: translateY(0) scale(0.98); }

/* ── Secondary ── */
.btn-secondary {
    background: rgba(255, 255, 255, 0.03); color: var(--text-main);
    border: 1px solid var(--border); backdrop-filter: blur(4px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--border-light);
    transform: translateY(-2px);
}

.btn-secondary:active { transform: translateY(0) scale(0.98); }

/* ── Ghost ── */
.btn-ghost {
    background: none; color: var(--text-muted); padding: 0.5rem 1rem;
}

.btn-ghost:hover {
    color: var(--text-main); background: rgba(255, 255, 255, 0.05);
}

/* ── Arrow Animation ── */
.btn .btn-arrow {
    transition: transform var(--transition-base); display: inline-flex;
}

.btn:hover .btn-arrow { transform: translateX(4px); }

/* ── Ripple Effect ── */
.ripple {
    position: absolute; border-radius: 50%; transform: scale(0);
    animation: rippleAnim 0.6s linear;
    background: rgba(255, 255, 255, 0.2); pointer-events: none;
}

.btn-primary .ripple { background: rgba(0, 0, 0, 0.2); }

@keyframes rippleAnim { to { transform: scale(4); opacity: 0; } }

/* ── Full Width ── */
.btn--full { width: 100%; }

/* ── Submit Button (Paper Airplane) ── */
.btn-submit { width: 100%; position: relative; height: 48px; }
.btn-text { transition: opacity var(--transition-base); }

.airplane-svg {
    position: absolute; width: 24px; height: 24px;
    top: 50%; left: 50%; margin-top: -12px; margin-left: -12px;
    opacity: 0; fill: var(--text-main); pointer-events: none;
}

.btn-submit.sending .btn-text { opacity: 0; }
.btn-submit.sending .airplane-svg { animation: flyAway 1.5s var(--easing) forwards; }

@keyframes flyAway {
    0%   { opacity: 1; transform: translate(0, 0) scale(1); }
    40%  { opacity: 1; transform: translate(20px, -20px) scale(1.1) rotate(15deg); }
    100% { opacity: 0; transform: translate(300px, -200px) scale(0.5) rotate(45deg); }
}